CN114910846B

CN114910846B - Phase-controllable MRI image enhanced super-structure surface device

Info

Publication number: CN114910846B
Application number: CN202110183929.2A
Authority: CN
Inventors: 赵乾; 池中海; 孟永钢; 郑卓肇
Original assignee: Tsinghua University; Beijing Tsinghua Changgeng Hospital
Current assignee: Tsinghua University; Beijing Tsinghua Changgeng Hospital
Priority date: 2021-02-10
Filing date: 2021-02-10
Publication date: 2024-04-23
Anticipated expiration: 2041-02-10
Also published as: CN114910846A

Abstract

The application relates to a phase-controllable MRI image enhancement super-structure surface device, in particular to a magnetic field enhancement device. The cylindrical support structure encloses a detection space. The cylindrical support structure has two spaced-apart opposed third and fourth ends. The plurality of magnetic field enhancement components are arranged at intervals on the cylindrical supporting structure and extend along the third end to the fourth end. The first annular conducting strip is arranged on the cylindrical supporting structure and is close to the third end. The first annular conductive sheet has a fifth opening. The fifth opening is at least partially located between two adjacent magnetic field enhancing assemblies. The first annular conductive sheet is electrically connected with the portions of the plurality of magnetic field enhancement assemblies at the third end. The second annular conductive sheet is arranged on the cylindrical supporting structure and is close to the fourth end. The second annular conductive sheet has a sixth opening. The sixth opening is at least partially located between two adjacent magnetic field enhancing assemblies. The phase of the induction field is controlled by adjusting the positions of the fifth opening and the sixth opening, so that the aim of accurately detecting the detection part is fulfilled.

Description

Phase-controllable MRI image enhanced super-structure surface device

Technical Field

The application relates to a nuclear magnetic resonance imaging technology, in particular to a magnetic field enhancement device.

Background

MRI (Magnetic Resonance Imaging ) is a non-invasive detection method, and is an important basic diagnosis technology in the fields of medicine, biology and neuroscience. The signal intensity transmitted by the traditional MRI device mainly depends on the intensity of the static magnetic field B0, and the signal-to-noise ratio and resolution of images can be improved and the scanning time can be shortened by adopting a high magnetic field system and even an ultra-high magnetic field system. However, an increase in static magnetic field strength brings about three problems: (1) The non-uniformity of the Radio Frequency (RF) field is increased, and the tuning difficulty is increased; (2) The heat production of human tissues is increased, so that potential safety hazards are brought, and adverse reactions such as dizziness, vomiting and the like are easy to occur for patients: (3) The acquisition cost is greatly increased, which is a burden for most small-scale hospitals. Therefore, how to use a static magnetic field strength as small as possible while achieving high imaging quality becomes a critical issue in MRI technology.

In order to solve the above-mentioned problems, the prior art provides a cylindrical super-structured surface device. The cylindrical super-structure surface device comprises a cylindrical supporting structure and a plurality of magnetic field enhancement assemblies which are arranged at intervals on the side wall of the circular arc-shaped supporting structure. The plurality of magnetic field enhancement assemblies are uniformly arranged on the side wall of the cylindrical supporting structure, so that the whole cylindrical super-structure surface device has isotropic characteristics. I.e. the induced field generated by the cylindrical super-structured surface device is independent of the angle of placement of the super-structured surface and only dependent on the phase of the incident field (source magnetic field). However, the existing cylindrical super-structured surface device cannot perform magnetic field phase regulation.

Disclosure of Invention

Based on this, it is necessary to provide a magnetic field enhancing device in view of the above-described problems.

A magnetic field enhancing device comprising:

a cylindrical support structure having two spaced-apart opposed third and fourth ends; a plurality of magnetic field enhancement assemblies disposed at intervals on the cylindrical support structure and extending along the third end toward the fourth end; and

The first annular conducting plate is arranged on the cylindrical supporting structure and is close to the third end, the first annular conducting plate is provided with a fifth opening, the fifth opening is at least partially positioned between two adjacent magnetic field enhancement assemblies, and the first annular conducting plate is electrically connected with the parts of the magnetic field enhancement assemblies positioned at the third end; and

The second annular conducting strip is arranged on the cylindrical supporting structure and is close to the fourth end, the second annular conducting strip is provided with a sixth opening, at least part of the sixth opening is positioned between two adjacent magnetic field enhancement assemblies, and the second annular conducting strip is electrically connected with the parts of the magnetic field enhancement assemblies positioned at the fourth end.

The magnetic field enhancement device provided by the embodiment of the application has the advantages that when the magnetic field enhancement device is placed in the excitation field of a magnetic resonance system, the direction of the induction field generated by the magnetic field enhancement device is always perpendicular to the plane formed by the cylindrical axis, the fifth opening and the sixth opening. The detection site may be placed in the detection space. The phase of the induction field is controlled by adjusting the positions of the fifth opening and the sixth opening, so that the aim of accurately detecting the detection part is fulfilled. The magnetic field enhancement device having the fifth opening and the sixth opening still has good resonance performance, and can enhance a signal field and improve image quality.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments or the conventional techniques of the present application, the drawings required for the descriptions of the embodiments or the conventional techniques will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for those skilled in the art.

FIG. 1 is a three-dimensional view of a magnetic field enhancing device provided in one embodiment of the present application;

FIG. 2 is an exploded view of a magnetic field enhancing device according to one embodiment of the present application;

FIG. 3 is a diagram showing a vertical relationship between an induction field and a fifth opening and a notch according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a resonance effect provided by an embodiment of the present application;

FIG. 5 is an internal magnetic field profile of a magnetic field enhancement device provided in accordance with one embodiment of the present application;

FIG. 6 is a side view of a magnetic field enhancement assembly provided in accordance with one embodiment of the present application;

FIG. 7 is a frequency contrast diagram of a magnetic field enhancement device according to an embodiment of the present application during a radio frequency transmit phase and a radio frequency receive phase;

FIG. 8 is a graph showing the effect of a magnetic field enhancement device according to an embodiment of the present application;

FIG. 9 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 10 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 11 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 12 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 13 is a perspective view of a magnetic field enhancement assembly provided in accordance with one embodiment of the present application;

FIG. 14 is a top view of a magnetic field enhancement assembly according to an embodiment of the present application;

FIG. 15 is a bottom view of a magnetic field enhancement assembly according to an embodiment of the present application;

FIG. 16 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 17 is a top view of a magnetic field enhancement assembly according to an embodiment of the present application;

FIG. 18 is a bottom view of a magnetic field enhancement assembly according to an embodiment of the present application;

FIG. 19 is a schematic diagram of a front projection of a first electrode layer and a second electrode layer on a first dielectric layer according to an embodiment of the present application;

FIG. 20 is a schematic diagram of a front projection shape of a first electrode layer and a second electrode layer on a first dielectric layer according to another embodiment of the present application;

FIG. 21 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 22 is a frequency contrast diagram of a magnetic field enhancement device according to an embodiment of the present application during a radio frequency transmit phase and a radio frequency receive phase;

FIG. 23 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 24 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 25 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 26 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 27 is a frequency contrast diagram of a magnetic field enhancement device according to an embodiment of the present application during a radio frequency transmit phase and a radio frequency receive phase;

FIG. 28 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 29 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 30 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 31 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 32 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 33 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 34 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 35 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 36 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 37 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 38 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 39 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 40 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 41 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 42 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 43 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application;

FIG. 44 is a block diagram of a magnetic field enhancement assembly provided in accordance with one embodiment of the present application;

FIG. 45 is a block diagram of a magnetic field enhancement assembly according to one embodiment of the present application.

Reference numerals illustrate:

The magnetic field enhancement device 20, the cylindrical support structure 50, the third end 51, the fourth end 53, the detection space 509, the magnetic field enhancement assembly 10, the first annular conductive tab 510, the second annular conductive tab 520, the fifth opening 501, the sixth opening 502, the axis 504, the central symmetry plane 506, the confinement structure 530, the first dielectric layer 100, the first surface 101, the second surface 102, the via 103, the first electrode layer 110, the second electrode layer 120, the third electrode layer 130, the first opening 411, the second opening 412, the third opening 413, the fourth opening 414, the first end 103, the second end 104, the fourth electrode layer 140, the first structure capacitor 150, the first switch control circuit 430, the first diode 431, the second diode 432, the first enhancement MOS 433, the second enhancement MOS transistor 434, the first external capacitor 440, the first end 103, the second end 104, the magnetic field enhancement device 20, the third end 51, the fourth end 53 the second structure capacitor 152, the third structure capacitor 153, the second switch control circuit 450, the third diode 451, the fourth diode 452, the third enhancement MOS transistor 453, the fourth enhancement MOS transistor 454, the second external capacitor 442, the third external capacitor 443, the first terminal 103, the second terminal 104, the third switch control circuit 460, the fifth diode 461, the sixth diode 462, the fifth enhancement MOS transistor 463, the sixth enhancement MOS transistor 464, the fourth external capacitor 444, the fifth external capacitor 445, the first sub-electrode layer 111, the first connection layer 190, the seventh control circuit 630, the third capacitor 223, the first inductor 241, the first switch circuit 631, the seventh diode 213, the eighth diode 214, the seventh enhancement MOS transistor 235, the eighth enhancement MOS transistor 236, the fifth electrode layer 141, the third inductor 243, the fourth structure capacitor 302, the fifth structure capacitor 303, the sixth structure capacitor 304, fourth capacitor 224, second direction a, first direction b, second resonant circuit 410, second dielectric layer 831, seventh electrode layer 832, eighth electrode layer 833, first depletion MOS 231, second depletion MOS 232, third surface 805, fifth end 881, sixth end 882.

Detailed Description

The present application will be further described in detail below with reference to examples, which are provided to illustrate the objects, technical solutions and advantages of the present application. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

The numbering of the components itself, e.g. "first", "second", etc., is used herein merely to distinguish between the described objects and does not have any sequential or technical meaning. The term "coupled" as used herein includes both direct and indirect coupling, unless stated otherwise. In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element in question must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

In the present application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

Referring to fig. 1 and 2, an embodiment of the present application provides a magnetic field enhancing device 20. The magnetic field enhancement device 20 includes a cylindrical support structure 50, a plurality of magnetic field enhancement assemblies 10, a first annular conductive sheet 510, and a second annular conductive sheet 520. The cylindrical support structure 50 encloses a detection space 509. The cylindrical support structure 50 has two spaced-apart opposed third and fourth ends 51, 53. The plurality of magnetic field enhancement assemblies 10 are spaced apart from the cylindrical support structure 50 and extend along the third end 51 toward the fourth end 53. The first annular conductive sheet 510 is disposed on the cylindrical support structure 50 and is adjacent to the third end 51. The first annular conductive sheet 510 has a fifth opening 501. The fifth opening 501 is at least partially located between two adjacent magnetic field enhancing assemblies 10. The first annular conductive sheet 510 is electrically connected to the portions of the plurality of magnetic field enhancement assemblies 10 located at the third end 51. The second annular conductive tab 520 is disposed on the cylindrical support structure 50 proximate the fourth end 53. The second annular conductive sheet 520 has a sixth opening 502. The sixth opening 502 is at least partially located between two adjacent magnetic field enhancing assemblies 10. The second annular conductive tab 520 is electrically connected to the portions of the plurality of magnetic field enhancement assemblies 10 at the fourth end 53.

The cylindrical support structure 50 encloses a detection space 509. The detection space 509 may be configured to accommodate a detection site. The part to be detected can be an arm, a leg, a waist and the like. The plurality of magnetic field enhancement assemblies 10 may be equally spaced from the cylindrical support structure 50.

In one embodiment, the cylindrical support structure 50 may have an axis 504 and a sidewall around the axis 504. A plurality of the magnetic field enhancement assemblies 10 may be equally spaced from the side walls of the cylindrical support structure 50. The plurality of magnetic field enhancement assemblies 10 are equally spaced apart to improve the uniformity of the local magnetic field. The side wall of the cylindrical supporting structure 50 may also be a hollow structure. The magnetic field enhancing components 10 may overlap the hollow structure.

The plurality of magnetic field enhancing assemblies 10 may be attached to the side wall of the cylindrical support structure 50 or may be disposed at intervals on the side wall of the cylindrical support structure 50, as long as the distances from the plurality of magnetic field enhancing assemblies 10 to the axis 504 of the cylindrical support structure 50 are equal. The equal distance of the plurality of magnetic field enhancing assemblies 10 from the axis 504 of the cylindrical support structure 50 may improve the uniformity of the local magnetic field.

The plurality of magnetic field enhancement assemblies 10 may be used to enhance the local area magnetic field strength after the magnetic field enhancement device 20 is placed in the magnetic resonance system to enhance the magnetic resonance detection effect. The plurality of magnetic field enhancement assemblies 10 may have a strip-like configuration and extend from the third end 51 toward the fourth end 53.

The first annular conductive piece 510 and the second annular conductive piece 520 are respectively disposed at the third end 51 and the fourth end 53. The first annular conductive tab 510 and the second annular conductive tab 520 may each be positioned end-to-end about the axis 504 of the tubular support structure 50 to form an annular structure. The fifth opening 501 is formed near the front and the rear of the first annular conductive sheet 510. The sixth opening 502 is formed near the end of the second annular conductive sheet 520.

The fifth opening 501 allows the first annular conductive sheet 510 to be disconnected from the head and tail ends. The sixth opening 502 allows the ends of the second annular conductive sheet 520 to be out of engagement. Thus, when the cylindrical support structure 50 is placed in the excitation field of the magnetic resonance system, no current loop is formed in the annular structure formed by the first annular conductive sheet 510 and the annular structure formed by the second annular conductive sheet 520. The phase of the induced magnetic field of the magnetic field enhancing means 20 can be adjusted by the position of the fifth opening 501 and the sixth opening 502.

The magnetic field enhancing device 10 is a phase-controllable MRI image enhancing super-structured surface device. The phase of the induced magnetic field of the phase-controllable MRI image enhanced super-structure surface device may be adjusted by the positions of the fifth opening 501 and the sixth opening 502.

The sixth opening 502 is at least partially located between two adjacent magnetic field enhancing assemblies 10. The fifth opening 501 is at least partially located between two adjacent magnetic field enhancing assemblies 10. Therefore, the sixth opening 502 or the fifth opening 501 may not be all attached to the surface of the magnetic field enhancing component 10. That is, the ends of the second annular conductive sheet 520 forming the sixth opening 502 are not all attached to the surface of the magnetic field enhancing component 10. The first annular conductive sheet 510 does not adhere to the surface of the magnetic field enhancing member 10 at all at the end portions of the fifth opening 501. Thus, the first annular conductive sheet 510 forms the head and tail ends of the fifth opening 501 that are not electrically connected by the magnetic field enhancing assembly 10. The ends of the second annular conductive sheet 520 that form the sixth opening 502 are not electrically connected by the magnetic field enhancing assembly 10. The first annular conductive sheet 510 and the second annular conductive sheet 520 cannot constitute a conductive path.

In one embodiment, the first annular conductive sheet 510 and the second annular conductive sheet 520 may be made of metal materials such as gold, silver, copper, etc.

Referring to fig. 3, when the magnetic field enhancing device 20 is placed in the excitation field of the magnetic resonance system, the direction of the induced field generated by the magnetic field enhancing device 20 is always perpendicular to the plane formed by the cylindrical axis 504, the fifth opening 501 and the sixth opening 502. The detection site may be placed in the detection space 509. The phase of the induction field is controlled by adjusting the positions of the fifth opening 501 and the sixth opening 502, so as to achieve the purpose of accurately detecting the detection part. It has been found experimentally that the magnetic field enhancing device 20 with the fifth opening 501 and the sixth opening 502 still has good resonance properties, and is capable of enhancing the signal field and improving the image quality.

Referring to fig. 4, the resonance performance of the magnetic field enhancement device 20 is not significantly different from the resonance performance of the first annular conductive sheet 510 and the second annular conductive sheet 520 in the closed structure, and the resonance performance of the magnetic field enhancement device 20 is not affected.

Referring to fig. 5, the magnetic field area within the magnetic field enhancement device 20 remains highly uniform for the detection-effective magnetic field area without causing a change in image contrast.

In one embodiment, the fifth opening 501 and the sixth opening 502 are located between two adjacent magnetic field enhancing assemblies 10. I.e. the first annular conductive tab 510 forming the fifth opening 501, extends end-to-end towards the gap between two adjacent magnetic field enhancing assemblies 10. The first and second ends of the second annular conductive sheet 520 forming the sixth opening 502 protrude toward the gap between two adjacent magnetic field enhancement assemblies 10. The magnetic field enhancement assembly 10 may have abrupt areas at the portion of the third end 51 contacting the first annular conductive sheet 510 and the portion of the fourth end 53 contacting the second annular conductive sheet 520. The abrupt area change causes abrupt resistance changes. The abrupt resistance causes abrupt field strength of the electric field, and the induced magnetic field also becomes abrupt. The magnetic field with mutation can monitor the detection part in a targeted manner, and the detection effect can be improved. In the excitation field, the magnetic field strength of the magnetic field enhancement assembly 10 is increased by the electric field induced at the head-to-tail ends of the first annular conductive sheet 510 and the second annular conductive sheet 520, and thus the magnetic field strength induced by the electric field is increased. The detection effect can be further improved by aligning the region in which the magnetic field increases with a specific detection portion.

In one embodiment, the cylindrical support structure 50 has a central plane of symmetry 506 located between the third end 51 and the fourth end 53. The fifth opening 501 and the sixth opening 502 are symmetrical about the central symmetry plane 506. The central symmetry plane 506 may bisect the cylindrical support structure 50 along a cross-section of the cylindrical support structure 50. The fifth opening 501 and the sixth opening 502 are each symmetrical about the central symmetry plane 506. The line connecting the center of the fifth opening 501 and the center of the sixth opening 502 may be parallel to the axis 504 of the cylindrical support structure 50.

The direction of the induced field due to the magnetic field enhancing means 20 is always parallel to the central symmetry plane 506. The symmetry of the fifth opening 501 and the sixth opening 502, respectively, with respect to the central symmetry plane 506 can thus increase the parallelism of the direction of the induced magnetic field generated by the magnetic field enhancing device 20 with respect to the central symmetry plane 506. The direction of the induced magnetic field of the magnetic field enhancement device 20 can be precisely adjusted by adjusting the position of the central symmetry plane 506.

In one embodiment, the arc length corresponding to the fifth opening 501 and the arc length corresponding to the sixth opening 502 are smaller than the arc length between two adjacent magnetic field enhancing assemblies 10. It will be appreciated that the fifth opening 501 is located on the circular track where the first circular conductive sheet 510 is located. The sixth opening 502 is located on the circular track where the second circular conductive sheet 520 is located. The first annular conductive sheet 510 has a portion located in the annular track removed to form the fifth opening 501. The second annular conductive sheet 520 forms the sixth opening 502 with a portion of the annular trace removed. The arc corresponding to the fifth opening 501 and the arc corresponding to the sixth opening 502 are located in the middle of two adjacent magnetic field enhancement assemblies 10. That is, the first annular conductive piece 510 forming the fifth opening 501 protrudes from the front end to the rear end toward the gap between two adjacent magnetic field enhancement assemblies 10, and the protruding distance may be equal, and the second annular conductive piece 520 forming the sixth opening 502 protrudes from the front end to the rear end toward the gap between two adjacent magnetic field enhancement assemblies 10, and the protruding distance may be equal. The above structure increases the strength of the electric field induced by the magnetic field enhancement assembly 10 at the front and rear ends of the first annular conductive sheet 510 and the second annular conductive sheet 520, and thus increases the magnetic field density induced by the electric field. The detection effect can be further improved by aligning the region of increased magnetic field density with a specific detection site.

In one embodiment, the arc length corresponding to the fifth opening 501 and the arc length corresponding to the sixth opening 502 are one third to one half of the arc length between two adjacent magnetic field enhancing assemblies 10.

Within this range, the contact areas between the two ends of the magnetic field enhancement unit 10 and the first annular conductive sheet 510 and the second annular conductive sheet 520 do not change too much, and power consumption due to heat generation can be avoided.

In one embodiment, at the third end 51, the magnetic field enhancement assembly 10 is sandwiched between the cylindrical support structure 50 and the first annular conductive sheet 510. At the fourth end 53, the magnetic field enhancement assembly 10 is sandwiched between the cylindrical support structure 50 and the second annular conductive sheet 520. Namely, the first annular conductive sheet 510 and the second annular conductive sheet 520 are sleeved on the side wall of the cylindrical supporting structure 50. One end of the magnetic field enhancement assembly 10 is directly attached to the side wall of the cylindrical support structure 50, and the first annular conductive sheet 510 is located on the side of the magnetic field enhancement assembly 10 away from the cylindrical support structure 50. The other end of the magnetic field enhancing assembly 10 is directly attached to the side wall of the cylindrical support structure 50. The second annular conductive sheet 520 is located on a side of the magnetic field enhancing assembly 10 remote from the cylindrical support structure 50.

The first annular conductive sheet 510 and the second annular conductive sheet 520 respectively press the two ends of the magnetic field enhancement assembly 10 against the two ends of the cylindrical supporting structure 50, which plays a role in fixing, can play a role in electric connection, and has a simple structure, and is convenient to install and detach. Referring to fig. 6, in one embodiment, the magnetic field enhancement assembly 10 includes a first electrode layer 110, a second electrode layer 120, and a first dielectric layer 100. The first dielectric layer 100 includes a first surface 101 and a second surface 102 disposed opposite each other. The first electrode layer 110 is disposed on the first surface 101. The first electrode layer 110 covers a portion of the first surface 101. The second electrode layer 120 is disposed on the second surface 102. The second electrode layer 120 covers a portion of the second surface 102. The orthographic projection of the first electrode layer 110 on the first dielectric layer 100 and the orthographic projection of the second electrode layer 120 on the first dielectric layer 100 are overlapped to form a first structural capacitor 150.

The first electrode layer 110 covering a part of the first surface 101 means that the first surface 101 is still partly uncovered by the first electrode layer 110. The second electrode layer 120 covering a part of the second surface 102 means that the second surface 102 is still partly uncovered by the second electrode layer 120. The first electrode layer 110 and the second electrode layer 120 overlap in part in the orthographic projection of the first dielectric layer 100. The portion of the first electrode layer 110 and the second electrode layer 120 that are disposed opposite to each other constitutes the first structural capacitor 150. The portion of the first electrode layer 110 and the second electrode layer 120, which do not overlap in the orthographic projection of the first dielectric layer 100, may serve as a transmission line, and serve as an equivalent inductance. The first structural capacitance 150 and the equivalent inductance may form an LC tank circuit. When the magnetic field enhancement device 20 is used in a low resonance frequency occasion, the first structural capacitor 150 with a small capacitance value can reduce the resonance frequency of the magnetic field enhancement devices 20 formed by the magnetic field enhancement assemblies 10 to the frequency of the radio frequency coil of the magnetic resonance system, so that the magnetic field intensity can be effectively improved.

The portion of the magnetic field enhancing assembly 10 that forms the first structural capacitance 150 produces a magnetic field that is parallel to the plane of the first dielectric layer 100. Whereas a magnetic field parallel to the first dielectric layer 100 is essentially undetectable, belonging to an ineffective magnetic field. The magnetic field generated by the portion of the magnetic field enhancing assembly 10 that constitutes the equivalent inductance is perpendicular to the first dielectric layer 100 and is effective to generate a magnetic field that is effective in the detection region.

In one embodiment, the area occupied by the overlapping portion of the orthographic projection of the first electrode layer 110 on the first dielectric layer 100 and the orthographic projection of the second electrode layer 120 on the first dielectric layer 100 is less than half the area of the first surface 101 or half the area of the second surface 102. Thus, the area of the first dielectric layer 100 constituting the first structural capacitance 150 is less than half the area of the first dielectric layer 100. By reducing the area of the first structural capacitance 150, the power consumption of the first structural capacitance 150 can be reduced. The area of the first dielectric layer 100 constituting the first structural capacitor 150 is smaller than half the area of the first dielectric layer 100, so that the coupling degree between the magnetic field enhancement component 10 and other cascading super-structure surfaces can be reduced, and the performance of the magnetic field enhancement component 10 is significantly improved.

The first dielectric layer 100 may function to support the first electrode layer 110 and the second electrode layer 120. The first dielectric layer 100 may have a rectangular plate-like structure. The first dielectric layer 100 may be an insulating material. In one embodiment, the material of the first dielectric layer 100 may be a glass fiber epoxy plate. The first electrode layer 110 and the second electrode layer 120 may have a rectangular plate-like structure. The materials of the first electrode layer 110 and the second electrode layer 120 may be composed of an electrically conductive non-magnetic material. In one embodiment, the materials of the first electrode layer 110 and the second electrode layer 120 may be metal materials such as gold, silver, copper, etc.

In one embodiment, the thicknesses of the first electrode layer 110 and the second electrode layer 120 may be equal. The first electrode layer 110, the second electrode layer 120, and the first dielectric layer 100 are stacked. The planes of the first electrode layer 110, the second electrode layer 120, and the first dielectric layer 100 may be substantially parallel.

Referring to fig. 6, a magnetic field enhancing assembly 10 is provided in accordance with an embodiment of the present application. The magnetic field enhancement assembly 10 includes a first dielectric layer 100, a first electrode layer 110, a second electrode layer 120, a fourth electrode layer 140, and a first switch control circuit 430. The first dielectric layer 100 includes opposing first and second surfaces 101, 102. The first electrode layer 110 is disposed on the first surface 101. The second electrode layer 120 and the fourth electrode layer 140 are disposed on the second surface 102. The first electrode layer 110 has an overlapping portion with the second electrode layer 120 and the fourth electrode layer 140, respectively, in front projection of the first dielectric layer 100. Both ends of the first switch control circuit 430 are connected to the first electrode layer 110 and the second electrode layer 120, respectively. The first switch control circuit 430 is configured to be turned on during a radio frequency transmitting phase and turned off during a radio frequency receiving phase.

The first dielectric layer 100 may be an insulating material. The first dielectric layer 100 may function to support the first electrode layer 110, the second electrode layer 120, and the fourth electrode layer 140. The first dielectric layer 100 may have a rectangular plate-like structure. The first dielectric layer 100 may be an insulating material. In one embodiment, the material of the first dielectric layer 100 may be a glass fiber epoxy plate. The first electrode layer 110 and the second electrode layer 120 may have a rectangular plate-like structure. The materials of the first electrode layer 110 and the second electrode layer 120 may be composed of an electrically conductive non-magnetic material. In one embodiment, the materials of the first electrode layer 110 and the second electrode layer 120 may be metal materials such as gold, silver, copper, etc.

In one embodiment, the thicknesses of the first electrode layer 110, the second electrode layer 120, and the fourth electrode layer 140 may be equal. The planes of the first electrode layer 110, the second electrode layer 120, and the fourth electrode layer 140, and the first dielectric layer 100 may be substantially parallel.

The first electrode layer 110 and the second electrode layer 120 have overlapping portions in the orthographic projection of the first dielectric layer 100. The fourth electrode layer 140 and the first electrode layer 110 have overlapping portions in the orthographic projection of the first dielectric layer 100. Thus, in the overlapping portion, the first electrode layer 110, the second electrode layer, and the first dielectric layer 100 may constitute a second structural capacitance 152. The first electrode layer 110, the fourth electrode layer 140, and the first dielectric layer 100 may constitute a third structural capacitance 153. The two structural capacitors are connected in series, so that the load effect can be effectively reduced, and the stability of the resonance frequency of the magnetic field enhancer is enhanced. In one embodiment, the first electrode layer 110 may completely cover the first dielectric layer 100.

The first electrode layer 110, the second electrode layer 120, and the fourth electrode layer 140 may form an equivalent inductance at a portion where the first dielectric layer 100 is not overlapped. The second structural capacitor 152, the third structural capacitor 153, and the equivalent inductance may constitute an LC oscillating circuit. When the magnetic field enhancement assembly 10 is placed in a magnetic resonance system, the resonant frequency of the LC oscillating circuit is adjusted under the action of the excitation field, so that the resonant frequency of the magnetic field enhancement assembly 20 formed by the magnetic field enhancement assemblies 10 is equal to the frequency of the radio frequency coil in the magnetic resonance system. The magnetic field enhancement device 20 formed by the cooperation of the plurality of magnetic field enhancement assemblies 10 can play a role in enhancing the radio frequency transmitting field and the radio frequency receiving field.

It will be appreciated that the radio frequency transmit phase and the radio frequency receive phase differ in time sequence by tens to thousands of milliseconds. The radio frequency power of the radio frequency transmit phase and the radio frequency receive phase differ by 3 orders of magnitude. The voltage on the structure capacitance during the rf transmission phase is between a few volts and a few hundred volts. And during the radio frequency receiving phase, the voltage across the structural capacitance is in the millivolt level.

Both ends of the first switch control circuit 430 are connected between the first electrode layer 110 and the second electrode layer 120. I.e. the first switch control circuit 430 may be connected in parallel with the second structural capacitance 152. Accordingly, when the first switch control circuit 430 is turned on, the first electrode layer 110 and the second electrode layer 120 are electrically connected. When the first switch control circuit 430 is turned off, the first electrode layer 110 and the second electrode layer 120 are disconnected. The turn-on voltage of the first switch control circuit 430 may be greater than 1 volt. That is, when the voltage difference between the first electrode layer 110 and the second electrode layer 120 is greater than 1 volt, the first switch control circuit 430 is turned on. When the voltage difference between the first electrode layer 110 and the second electrode layer 120 is less than 1 volt, the first switch control circuit 430 is turned off.

Referring to fig. 7, in the rf transmission stage, the first switch control circuit 430 is turned on due to a large voltage difference across the structure capacitor. The first electrode layer 110 and the second electrode layer 120 are electrically connected. At this time, the first electrode layer 110 and the second electrode layer 120 cannot form the second structural capacitor 152. That is, the magnetic field enhancement assembly 20 constituted by a plurality of the magnetic field enhancement assemblies 10 does not have a resonance function in the frequency band of interest. The magnetic field enhancement assembly 10 is therefore incapable of enhancing the radio frequency transmit field.

In the rf receiving stage, the voltage difference between the first electrode layer 110 and the second electrode layer 120 is smaller, the first switch control circuit 430 is turned off, and the first electrode layer 110 and the second electrode layer are turned off. The first electrode layer 110 and the second electrode layer 120 form the second structural capacitance 152 at this time. The magnetic field amplifying assembly 20 formed by the plurality of magnetic field amplifying assemblies 10 has a good resonance frequency during the radio frequency receiving phase. The magnetic field enhancement assembly 10 may provide enhancement to the radio frequency transmit field.

Referring to fig. 8, a magnetic field enhancing assembly 10 according to the prior art and an embodiment of the present application provides a MRI image enhancement effect map.

A is a body coil commonly adopted by a magnetic resonance system, the image signal-to-noise ratio is very low, and the particle sensation is serious;

b when the magnetic field enhancing assembly 10 is not provided with the first switch control circuit 430, a lot of artifacts appear in the formed image due to the magnetic field enhancing assembly 10 interfering with the radio frequency transmission field;

The magnetic field enhancement device 20 formed by the plurality of magnetic field enhancement components 10 provided by the embodiment of the application has high image signal to noise ratio, clear and fine image and no introduction of artifacts. Thus, the magnetic field enhancement device 20 formed by a plurality of the magnetic field enhancement assemblies 10 has better sequence versatility.

In the magnetic field enhancement assembly 10 according to the embodiment of the present application, the first switch control circuit 430 is configured to be turned on during a radio frequency transmitting phase and turned off during a radio frequency receiving phase. Therefore, during the rf emission phase, the first electrode layer 110 and the second electrode layer 120 are shorted, and cannot form the second structural capacitor 152. The magnetic field enhancement assembly 10 cannot enhance the radio frequency emission field, so that adverse effects of magnetic field enhancement on human bodies can be effectively reduced, and meanwhile, artifacts of images of the radio frequency emission field interfered by the magnetic field enhancement assembly 10 can be eliminated.

In one embodiment, the first switch control circuit 430 may also be connected between the first electrode layer 110 and the fourth electrode layer 140. The first switch control circuit 430 is turned on during the rf emission phase such that the first electrode layer 110 and the fourth electrode layer 140 are shorted, thereby enabling a further reduction of the effect of the magnetic field enhancement assembly 10 on the magnetic field enhancement during the rf emission phase.

The first switch control circuit 430 is turned off during the rf receiving phase, and the first electrode layer 110 and the fourth electrode layer 140 can form the third structural capacitor 153. The third structural capacitor 153 and the second structural capacitor 152 cooperate to further enhance the magnetic field enhancement effect.

In one embodiment, one end of the first switch control circuit 430 is connected to a portion where the first electrode layer 110 and the second electrode layer 120 overlap in the orthographic projection of the first dielectric layer 100. The other end of the first switch control circuit 430 is connected to a portion where the second electrode layer 120 and the first electrode layer 110 overlap in the front projection of the first dielectric layer 100. That is, the first switch control circuit 430 is connected to the first electrode layer 110 at a position that constitutes the second structure capacitor 152. It is thus possible to avoid that the first switch control circuit 430 is connected to a portion of the first electrode layer 110 that does not constitute the second structural capacitance 152 and the third structural capacitance 153. The portion of the first electrode layer 110 that does not form the second structure capacitor 152 and the third structure capacitor 153 has an equivalent inductance function, so as to avoid affecting the portion of the first electrode layer 110 that forms the equivalent inductance.

Referring to fig. 9, in one embodiment, the magnetic field enhancement assembly further includes a first external capacitor 440. Both ends of the first external capacitor 440 are respectively connected to the first electrode layer 110 and the second electrode layer 120. The first external capacitor 440 may be a tunable capacitor connected in parallel with the first electrode layer 110 and the second electrode layer 120. The resonance performance of the magnetic field enhancement device 20 formed by the magnetic field enhancement assembly 10 can be adjusted by the capacitive cooperation of the first external capacitor 440 and the structure formed by the first electrode layer 110, the second electrode layer and the first dielectric layer 100.

The first external capacitor 440 may be a fixed capacitor or an adjustable capacitor. When the use condition of the magnetic field enhancement assembly 10 is determined, for example, the frequency of the radio frequency coil is determined, a suitable fixed capacitance may be selected, so that the fixed capacitance is matched with the structural capacitance formed by the first electrode layer 110, the second electrode layer and the first dielectric layer 100, so that the resonance frequency of the magnetic field enhancement device 20 formed by the magnetic field enhancement device 10 is equal to the frequency of the radio frequency coil, and further the magnetic field enhancement effect is achieved. When the environment in which the magnetic field enhancement device 10 is used is not determined, such as the frequency of a radio frequency coil, an adjustable capacitance may be employed in the magnetic field enhancement device 10. The resonance frequency of the magnetic field enhancement device 20 formed by the magnetic field enhancement device 10 can be adjusted by adjusting the adjustable capacitance so that the magnetic field enhancement device 10 is suitable for different environments.

Referring to fig. 10, in one embodiment, the first switch control circuit 430 includes a first diode 431 and a second diode 432. An anode of the first diode 431 is connected to the first electrode layer 110. The cathode of the first diode 431 is connected to the second electrode layer 120. The cathode of the second diode 432 is connected to the first electrode layer 110, and the anode of the second diode 432 is connected to the second electrode layer 120.

It is understood that the turn-on voltage of the first diode 431 and the second diode 432 may be between 0 volt and 1 volt. In one embodiment, the turn-on voltage of the first diode 431 and the second diode 432 may be 0.8V. The first diode 431 and the second diode 432 are respectively connected in series between the first electrode layer 110 and the second electrode layer, and the first diode 431 and the second diode 432 are reversely connected.

Due to the alternating nature of radio frequency. The induced voltage generated by the first electrode layer 110 and the second electrode layer 120 is also an alternating voltage. In the radio frequency emission phase, the turn-on voltage of the first diode 431 and the second diode 432 has been exceeded due to the voltage difference between the first electrode layer 110 and the second electrode layer 120. Therefore, whichever of the first electrode layer 110 and the second electrode layer 120 has a higher voltage, one of the first diode 431 and the second diode 432 is always in an on state. Thus electrically connecting the first electrode layer 110 and the second electrode layer.

And in the rf receiving stage, since the voltage difference between the first electrode layer 110 and the second electrode layer is smaller than the turn-on voltage of the first diode 431 and the second diode 432. Therefore, the first diode 431 and the second diode 432 are in a non-conductive state regardless of which of the first electrode layer 110 and the second electrode layer 120 is high in voltage.

Referring to fig. 11, in one embodiment, the first switch control circuit 430 further includes a first enhancement MOS transistor 433 and a second enhancement MOS transistor 434. The source of the first enhancement MOS transistor 433 is connected to the second electrode layer 120. The drain electrode of the first enhancement MOS transistor 433 is connected to the first electrode layer 110. The gate of the first enhancement MOS transistor 433 is connected to the first electrode layer 110. The source of the second enhancement MOS transistor 434 is connected to the first electrode layer 110. The drain of the second enhancement MOS transistor 434 is connected to the second electrode layer. The gate of the second enhancement MOS transistor 434 is connected to the second electrode layer 120. Namely, the first enhancement type MOS tube 433 and the second enhancement type MOS tube 434 are reversely connected.

The first enhancement MOS transistor 433 and the second enhancement MOS transistor 434 are not turned on when the gate voltage is less than the threshold voltage, that is, a conductive channel can occur only when the magnitude of the gate voltage is greater than the threshold voltage thereof.

It will be appreciated that during the rf emission phase, since the voltage difference between the first electrode layer 110 and the second electrode layer 120 has exceeded the threshold voltage at which the first enhancement MOS transistor 433 and the second enhancement MOS transistor 434 are turned on, no matter which of the first electrode layer 110 and the second electrode layer is high, one of the first enhancement MOS transistor 433 and the second enhancement MOS transistor 434 is in an on state. Thus electrically connecting the first electrode layer 110 and the second electrode layer.

In the rf receiving stage, the voltage difference between the first electrode layer 110 and the second electrode layer is smaller than the on threshold voltage of the first enhancement MOS transistor 433 and the second enhancement MOS transistor 434. Therefore, regardless of which of the first electrode layer 110 and the second electrode layer 120 has a high voltage, the first enhancement MOS transistor 433 and the second enhancement MOS transistor 434 are in a non-conductive state.

Referring to fig. 12, the present application also provides a magnetic field enhancing assembly 10. The magnetic field enhancement assembly 10 includes a first electrode layer 110, a second electrode layer 120, a first dielectric layer 100, and a first switch control circuit 430. The first dielectric layer 100 includes a first surface 101 and a second surface 102 disposed opposite each other. The first electrode layer 110 is disposed on the first surface 101, and the first electrode layer 110 covers a portion of the first surface 101. The second electrode layer 120 is disposed on the second surface 102. The second electrode layer 120 covers a portion of the second surface 102. The orthographic projection of the first electrode layer 110 on the first dielectric layer 100 and the orthographic projection of the second electrode layer 120 on the first dielectric layer 100 are overlapped to form a first structural capacitor 150. The first switch control circuit 430 is connected between the first electrode layer 110 and the second electrode layer 120. The first switch control circuit 430 is configured to be turned on during a radio frequency transmitting phase and turned off during a radio frequency receiving phase. The implementation of the first switch control circuit 430 may be the same as or similar to the above embodiment, and will not be described herein.

The first electrode layer 110 covering a part of the first surface 101 means that the first surface 101 is still partly uncovered by the first electrode layer 110. The second electrode layer 120 covering a part of the second surface 102 means that the second surface 102 is still partly uncovered by the second electrode layer 120. The first electrode layer 110 and the second electrode layer 120 overlap in part in the orthographic projection of the first dielectric layer 100. The portion of the first electrode layer 110 and the second electrode layer 120 that are disposed opposite to each other constitutes the first structural capacitor 150. The portion of the first electrode layer 110 and the second electrode layer 120, which do not overlap in the orthographic projection of the first dielectric layer 100, may serve as a transmission line, and serve as an equivalent inductance. The first structural capacitance 150 and the equivalent inductance may form an LC tank circuit. When the first structure capacitor 150 is used in a low resonance frequency occasion, a large capacitance is not required to enable the resonance frequency of the magnetic field enhancement device 20 formed by the magnetic field enhancement assemblies 10 to be reduced to the working frequency of the magnetic resonance system, so that the magnetic field strength can be effectively improved.

Referring to fig. 13-15, in one embodiment, the first dielectric layer 100 includes opposing first and second ends 103, 104. The first electrode layer 110 extends from the second end 104 towards the first end 103. The second electrode layer 120 extends from the first end 103 towards the second end 104. The orthographic projection of the first electrode layer 110 on the first dielectric layer 100 overlaps the orthographic projection of the second electrode layer 120 on the first dielectric layer 100 to form the first structural capacitor 150. That is, the first electrode layer 110 and the second electrode layer 120 extend from opposite ends of the first dielectric layer 100 toward the middle of the first dielectric layer 100, respectively. The first electrode layer 110 and the second electrode layer 120 have overlapping portions in the front projection of the first dielectric layer 100. The overlapping portion is distant from both ends of the first dielectric layer 100.

In one embodiment, the length of the first electrode layer 110 and the second electrode layer 120 is less than three-fourths of the length of the first dielectric layer 100 and greater than one-fourth of the length of the first dielectric layer 100. In this range, the capacitance of the first capacitor 150 is smaller, so that the power consumption can be reduced. The effective inductor is longer in length, so that the magnetic field can be effectively enhanced, and the image signal-to-noise ratio improving effect of the magnetic field enhancing assembly 10 is improved.

The overlapping portion of the orthographic projections of the first electrode layer 110 and the second electrode layer 120 is located in the middle of the first dielectric layer 100. In the overlapping portion, the first electrode layer 110, the first dielectric layer 100, and the second electrode layer 120 constitute the first structural capacitance 150. The first electrode layer 110 and the second electrode layer 120 may form a transmission line at a portion where the first dielectric layer 100 is not overlapped, and function as an inductance. The first electrode layer 110 and the second electrode layer 120 may also serve as equivalent inductances at the non-stacked portions of the first dielectric layer 100. The equivalent inductance and the first structural capacitor 150 form an LC tank circuit.

The first electrode layer 110 and the second electrode layer 120 have the same width in the shape of a bar and have the same extension direction. The extending directions of the first electrode layer 110 and the second electrode layer 120 may be on a straight line, so that the width of the magnetic field enhancing member 10 can be reduced, and the volume of the magnetic field enhancing member 10 can be reduced.

In one embodiment, the portion of the first electrode layer 110 and the second electrode layer 120 that coincides with the orthographic projection of the first dielectric layer 100 is located in the middle of the first dielectric layer 100. The first structural capacitance 150 is located in the middle of the first dielectric layer 100.

The middle portion of the first dielectric layer 100 may be a portion of the first dielectric layer 100 away from an edge of the first dielectric layer 100. The middle of the first dielectric layer 100 may be the middle of the first dielectric layer 100, or may be a position that is far to the left or far to the right in the middle of the first dielectric layer 100. The first structure capacitor 150 is located in the middle of the first dielectric layer 100, which can effectively improve the symmetry of the structure of the magnetic field enhancement assembly 10, thereby improving the uniformity of the magnetic field.

In one embodiment, the target frequency range of the magnetic field enhancement assembly 10 may be 60MHz to 150MHz. In one embodiment, the target frequency range of the magnetic field enhancement assembly 10 may be 63.8MHz (1.5T for the main magnetic field B _O of the magnetic resonance system) or 128MHz (3T for the main magnetic field B _O of the magnetic resonance system). The first dielectric layer 100 may have a rectangular shape. The length of the first dielectric layer 100 may be 250 millimeters. The length of the portion where the front projections of the first electrode layer 110 and the second electrode layer 120 overlap with each other in the front projection of the first dielectric layer 100 may be 20 mm. I.e. the length of the magnetic field enhancing assembly 10 capable of generating an effective magnetic field is 230 mm. The area of the magnetic field enhancing assembly 10 capable of generating an effective magnetic field is significantly increased.

In one embodiment, one end of the first switch control circuit 430 is connected to the first electrode layer 110 at the middle of the first dielectric layer 100. The other end of the first switch control circuit 430 is connected to a position where the second electrode layer 120 is located in the middle of the first dielectric layer 100. I.e. the two ends of the first switch control circuit 430 are connected to the two plates of the first capacitor 150. The connection structure can avoid connecting both ends of the first switch control circuit 430 to the first electrode layer 110 and the second electrode layer 120 to form a portion of equivalent inductance, and thus can avoid the first switch control circuit 430 from affecting the portion of equivalent inductance.

Referring to fig. 16-18, in one embodiment, the magnetic field enhancement assembly 10 further includes a third electrode layer 130 disposed on the first surface 101. The third electrode layer 130 extends from the first end 103 towards the second end 104. The third electrode layer 130 covers a portion of the first surface 101 and is spaced apart from the first electrode layer 110. The second electrode layer 120 is electrically connected to the third electrode layer 130.

The thickness of the third electrode layer 130 may be the same as the thickness of the first electrode layer 110. The third electrode layer 130 may be connected to the second electrode layer 120 by bypassing the first dielectric layer 100. The third electrode layer 130 may also be connected to the second electrode layer 120 by a wire passing through the first dielectric layer 100. The portions of the first electrode layer 110 and the third electrode layer 130 that do not overlap the second electrode layer 120 may have an inductive effect when the magnetic field enhancing assembly 10 is placed in an excitation field of a magnetic resonance system.

The third electrode layer 130 may extend from the first end 103 of the first dielectric layer 100 toward the second end 104 and gradually approach the second electrode layer 120. The third electrode layer 130 is insulated from the first electrode layer 110, thereby preventing the first structural capacitor 150 formed by the first electrode layer 110 and the second electrode layer 120 from being shorted. The first electrode layer 110 and the third electrode layer 130 are disposed on the same side of the first dielectric layer 100. Accordingly, when the magnetic field enhancement assembly 10 is mounted to a bracket, the first surface 101 is mounted toward a side away from the middle, and damage to the first electrode layer 110 and the third electrode layer 130 by the bracket can be prevented.

In one embodiment, the length of the third electrode layer 130 is less than one-half the length of the first electrolyte layer 100. The length of the third electrode layer 130 is greater than one third of the length of the first dielectric layer 100. In this range, the equivalent inductance formed by the third electrode layer 130 has a larger length, and the area of the magnetic field enhancement unit 10 for generating the effective magnetic field can be effectively increased.

In one embodiment, the third electrode layer 130 is in a strip shape, and the extension direction and width of the third electrode layer 130 are the same as those of the first electrode layer 110. That is, the widths of the third electrode layer 130 and the first electrode layer 110 may be the same, and the third electrode layer 130 and the first electrode layer 110 may be positioned on the same straight line. The width of the first dielectric layer 100 may be equal to the width of the third electrode layer 130 and the first electrode layer 110, or slightly greater than the widths of the third electrode layer 130 and the first electrode layer 110. The width of the first dielectric layer 100 can be reduced as much as possible.

In one embodiment, the first dielectric layer 100 is provided with a via 103. An electrode material is disposed in the via 103. The third electrode layer 130 is electrically connected to the second electrode layer 120 through the electrode material. The electrode material may be the same as the material of the third electrode layer 130 and the second electrode layer 120, and thus the resistance may be reduced. In one embodiment, the electrode material in the via 103 is integrally formed with the first electrode and the third electrode layer 130.

In one embodiment, an end of the third electrode layer 130 near the first electrode layer 110 coincides with the orthographic projection of the via 103. The end of the second electrode layer 120 remote from the first electrode layer 110 coincides with the orthographic projection of the via 103. I.e. the third electrode layer 130 is in contact with the electrode material located in the via 103 close to the first surface 101. The second electrode layer 120 is in contact with the electrode material in the via 103 near the second surface 102. The third electrode layer 130, the second electrode layer 120 are thus electrically connected by the electrode material in the via 103.

Referring to fig. 19, in one embodiment, an end of the first electrode layer 110 near the second electrode layer 120 has a first opening 411. The second electrode layer 120 has a second opening 412 at an end near the first electrode layer 110. The orthographic projections of the first opening 411 and the second opening 412 on the first dielectric layer 100 coincide. The first opening 411 and the second opening 412 may have the same size. The first opening 411 and the second opening 412.

The overlapping portions of the first electrode layer 110 and the second electrode layer 120 in the orthographic projection of the first dielectric layer 100 may constitute the first structural capacitance 150 when the magnetic field enhancing assembly 10 is placed in an excitation field in a magnetic resonance system. The first opening 411 and the second opening 412 can optimize local magnetic field distribution, and can improve the detection effect of the specific position of the detection part.

Referring to fig. 20, in one embodiment, an end of the first electrode layer 110 near the second electrode layer 120 has a third opening 413. The third opening 413 is spaced from the first opening 411. The second electrode layer 120 has a fourth opening 414 near the end of the first electrode layer 110. The fourth opening 414 is spaced from the second opening 412. The orthographic projection of the third opening 413 and the fourth opening 414 on the first dielectric layer 100 coincides. It is understood that the first opening 411 and the third opening 413 may have the same shape and size. The second opening 412 and the fourth opening 414 may be the same size and shape. The distance between the first opening 411 and the third opening 413 may be the same. The distance between the second opening 412 and the fourth opening 414 may be the same. The third opening 413 and the fourth opening 414 may be located at overlapping portions of the first electrode layer 110 and the second electrode layer 120 orthographically projected on the first dielectric layer 100. The third opening 413 and the fourth opening 414 further optimize local magnetic field distribution, so as to improve the detection effect of the specific position of the detection part. When the magnetic field enhancement assembly 10 is the embodiment described above including the first electrode layer 110, the second electrode layer 120, and the fourth electrode layer 140, the first annular conductive sheet 510 is electrically connected to the second electrode layer 120. The second annular conductive sheet 520 is electrically connected to the fourth electrode layer 140.

When the magnetic field enhancement assembly 10 is an embodiment including only the first electrode layer 110 and the second electrode layer 120, the first annular conductive sheet 510 is electrically connected to the first electrode layer 110. The second annular conductive sheet 520 is electrically connected to the second electrode layer 120.

Referring to fig. 21, in one embodiment, the magnetic field enhancement assembly 10 further includes a second external capacitor 442, a third external capacitor 443, and a second switch control circuit 450. One end of the third external capacitor 443 is connected to the second electrode layer 120. The other end of the third external capacitor 443 is connected to one end of the second external capacitor 442 and one end of the second switch control circuit 450, respectively. The other end of the second external capacitor 442 and the other end of the second switch control circuit 450 are connected to the first electrode layer 110, respectively. The second switch control circuit 450 is configured to be turned on during a radio frequency transmitting phase and turned off during a radio frequency receiving phase.

The first electrode layer 110, the second electrode layer 120, and the fourth electrode layer 140 may form an equivalent inductance at a portion where the first dielectric layer 100 is not overlapped. The second structural capacitor 152, the third structural capacitor 153, and the equivalent inductance may constitute an LC oscillating circuit. So that the resonance frequency of the magnetic field enhancing device 20 constituted by a plurality of said magnetic field enhancing assemblies 10 is equal to the frequency of the radio frequency coil in the magnetic resonance system. When the magnetic field enhancing device 20 with the magnetic field enhancing assembly 10 is placed in a magnetic resonance system, a plurality of the magnetic field enhancing assemblies 10 cooperate to enhance the magnetic field under the influence of the excitation field.

The other end of the third external capacitor 443 is connected to one end of the second external capacitor 442 and one end of the second switch control circuit 450, respectively. The other end of the second switch control circuit 450 is connected to the first electrode layer 110. That is, the other end of the second switch control circuit 450 is connected between the second external capacitor 442 and the third external capacitor 443. Therefore, when the second switch control circuit 450 is turned on, the second external capacitor 442 is shorted. Only the third external capacitor 443 is connected between the first electrode layer 110 and the second electrode layer 120. When the second switch control circuit 450 is turned off, the second external capacitor 442 and the third external capacitor 443 are connected in series between the first electrode layer 110 and the second electrode layer 120.

The turn-on voltage of the second switch control circuit 450 may be greater than 1 volt. That is, when the voltage difference between the first electrode layer 110 and the second electrode layer 120 is greater than 1 volt, the second switch control circuit 450 is turned on. The second switch control circuit 450 is turned off when the voltage difference between the first electrode layer 110 and the second electrode layer 120 is less than 1 volt.

During the rf transmission phase, the second switch control circuit 450 is turned on due to the large voltage difference across the second structural capacitor 152. The second external capacitor 442 is shorted. Only the third external capacitor 443 is connected between the first electrode layer 110 and the second electrode layer 120. The degree of detuning of the magnetic field enhancement assembly 20 formed by the plurality of magnetic field enhancement assemblies 10 during the rf transmission phase can be reduced or avoided by providing a suitable third external capacitor 443. The resonance frequency of the magnetic field enhancement device 20 formed by the magnetic field enhancement assemblies 10 can be precisely adjusted through the third external capacitor 443, so that the original magnetic field strength of the detected region is maintained, and the interference of the magnetic field enhancement assemblies 10 on the radio frequency emission stage is eliminated. The original magnetic field intensity of the detected region is maintained, so that the interference of the magnetic field enhancement assembly 10 to the radio frequency emission stage can be eliminated, and the clinical practicability of the magnetic field enhancement assembly 20 formed by a plurality of magnetic field enhancement assemblies 10 can be effectively improved. So that the magnetic field enhancement assembly 20 is applicable to all sequences of magnetic resonance systems. And can effectively reduce the adverse effect of the magnetic field enhancement on human body.

During the rf receiving phase, the voltage difference across the second capacitor 152 is small, and the second switch control circuit 450 is turned off. In the rf receiving stage, the second external capacitor 442 and the third external capacitor 443 are connected in series between the first electrode layer 110 and the second electrode layer 120.

Referring to fig. 22, by providing the second external capacitor 442 and the third external capacitor 443, the magnetic field enhancement device 20 formed by the plurality of magnetic field enhancement components 10 can have a good resonant frequency during the rf receiving stage. The magnetic field enhancement device 20 formed by the plurality of magnetic field enhancement assemblies 10 can enhance the rf emission field.

The second external capacitor 442 and the third external capacitor 443 may be fixed capacitors or tunable capacitors. When the environment in which the magnetic field enhancement assembly 10 is used is determined, for example, the frequency of a radio frequency coil, a suitable fixed capacitance may be selected so that the resonant frequency of the magnetic field enhancement device 20 formed by the magnetic field enhancement device 10 is equal to the frequency of the radio frequency coil, thereby acting to enhance the magnetic field. When the environment in which the magnetic field enhancement device 10 is used is not determined, for example, the frequency of the rf coil is not determined, the second external capacitor 442 and the third external capacitor 443 may use tunable capacitors. The resonant frequency of the magnetic field enhancing device 20 formed by the magnetic field enhancing assembly 10 can be adjusted by adjusting the adjustable capacitance to adapt the magnetic field enhancing device 10 to different environments.

In the rf emission stage of the magnetic field enhancement assembly 10 according to the embodiment of the present application, the second switch control circuit 450 is turned on due to the larger voltage difference between the first electrode layer 110 and the second electrode layer 120. Only the third external capacitor 443 is connected between the first electrode layer 110 and the second electrode layer 120. The third external capacitor 443 can reduce the detuning degree of the rf emission phase of the magnetic field enhancement device 20 formed by a plurality of the magnetic field enhancement components 10. By providing the third external capacitor 443, the magnetic field strength of the region under test in the magnetic resonance system can be the same during the rf transmission phase when the magnetic field enhancement assembly 10 is used and before the magnetic field enhancement assembly 10 is used. Therefore, during the radio frequency transmission phase, the magnetic field intensity of the tested area in the magnetic resonance system is kept consistent, that is, the tested area can be kept at the original magnetic field intensity, the interference of the magnetic field enhancement assembly 10 on the radio frequency transmission phase is eliminated, and the clinical practicability of the magnetic field enhancement assembly 20 formed by a plurality of magnetic field enhancement assemblies 10 can be effectively improved. So that the magnetic field enhancement assembly 20 is applicable to all sequences of magnetic resonance systems. The adverse effect of the magnetic field enhancement on the human body can be effectively reduced.

Referring to fig. 23, in one embodiment, the second switch control circuit 450 includes a third diode 451 and a fourth diode 452. An anode of the third diode 451 is connected to the first electrode layer 110. The cathode of the fourth diode 452 is connected to the first electrode layer 110. One end of the third external capacitor 443 is connected to the second electrode layer 120. The other end of the third external capacitor 443 is connected to the cathode of the third diode 451, the anode of the fourth diode 452, and one end of the second external capacitor 442, respectively. The other end of the second external capacitor 442 is connected to the first electrode layer 110.

It is understood that the turn-on voltage of the third diode 451 and the fourth diode 452 may be between 0 volts and 1 volt. In one embodiment, the turn-on voltage of the third diode 451 and the fourth diode 452 may be 0.8V. The third diode 451 and the fourth diode 452 are respectively connected in series between the first electrode layer 110 and the second electrode layer, i.e., the third diode 451 and the fourth diode 452 are reversely connected.

Due to the alternating nature of radio frequency. The induced voltage generated by the first electrode layer 110 and the second electrode layer 120 is also an alternating voltage. In the radio frequency emission phase, the turn-on voltage of the third diode 451 and the fourth diode 452 has been exceeded due to the voltage difference between the first electrode layer 110 and the second electrode layer 120. Therefore, whichever of the first electrode layer 110 and the second electrode layer 120 has a high voltage, one of the third diode 451 and the fourth diode 452 is always in an on state. The second external capacitor 442 is shorted.

And in the rf receiving stage, since the voltage difference between the first electrode layer 110 and the second electrode layer is smaller than the turn-on voltage of the third diode 451 and the fourth diode 452. Therefore, no matter which of the first electrode layer 110 and the second electrode layer 120 has a high voltage, the third diode 451 and the fourth diode 452 are in a non-conductive state, and the second external capacitor 442 and the third external capacitor 443 are connected in series between the first electrode layer 110 and the second electrode layer 120 during the radio frequency receiving stage.

Referring to fig. 24, in one embodiment, the second switch control circuit 450 further includes a third enhancement MOS transistor 453 and a fourth enhancement MOS transistor 454. The drain electrode of the third enhancement MOS transistor 453 is connected to the first electrode layer 110. The gate 453 of the third enhancement MOS transistor is connected to the first electrode layer 110. The source of the fourth enhancement MOS transistor 454 is connected to the first electrode layer 110. One end of the third external capacitor 443 is connected to the second electrode layer 120. The other end of the third external capacitor 443 is connected to the source of the third enhancement MOS transistor 453, the drain of the fourth enhancement MOS transistor 454, the gate of the fourth enhancement MOS transistor 454, and one end of the second external capacitor 442, respectively. The other end of the second external capacitor 442 is connected to the first electrode layer 110. That is to say, the third enhancement MOS transistor 453 and the fourth enhancement MOS transistor 454 are reversely connected.

The third enhancement MOS transistor 453 and the fourth enhancement MOS transistor 454 are not turned on when the gate voltage is smaller than the threshold voltage, that is, a conductive channel can occur only when the magnitude of the gate voltage is larger than the threshold voltage thereof.

It will be appreciated that during the rf emission phase, since the voltage difference between the first electrode layer 110 and the second electrode layer 120 has exceeded the threshold voltage at which the third enhancement MOS transistor 453 and the fourth enhancement MOS transistor 454 are turned on, no matter which of the first electrode layer 110 and the second electrode layer is high, one of the third enhancement MOS transistor 453 and the fourth enhancement MOS transistor 454 is in an on state. The second external capacitor 442 is shorted.

In the rf receiving stage, the voltage difference between the first electrode layer 110 and the second electrode layer is smaller than the on threshold voltage of the third enhancement MOS transistor 453 and the fourth enhancement MOS transistor 454. Therefore, the third enhancement MOS transistor 453 and the fourth enhancement MOS transistor 454 are in a non-conductive state no matter which of the first electrode layer 110 and the second electrode layer 120 is high in voltage. That is, during the rf receiving phase, the second external capacitor 442 and the third external capacitor 443 are connected in series between the first electrode layer 110 and the second electrode layer 120.

The second switch control circuit 450 is turned off during the rf receiving phase, and the first electrode layer 110 and the fourth electrode layer 140 can form the third structural capacitor 153. The third structural capacitor 153 and the second structural capacitor 152 cooperate to further enhance the magnetic field enhancement effect.

In one embodiment, one end of the second switch control circuit 450 is connected to a position where the first electrode layer 110 and the second electrode layer 120 have overlapping portions in the orthographic projection of the first dielectric layer 100. The other end of the second switch control circuit 450 is connected to a position where the second electrode layer 120 and the first electrode layer 110 have a superposition portion in the front projection of the first dielectric layer 100. That is, the second switch control circuit 450 is connected to the first electrode layer 110 at a position that forms part of the second capacitor 152. It is therefore possible to avoid that the second switch control circuit 450 is connected to a portion of the first electrode layer 110 that does not constitute the second structural capacitance 152 and the third structural capacitance 153. Since the first electrode layer 110 does not form part of the second structure capacitor 152 and the third structure capacitor 153, the first electrode layer has an equivalent inductance. The above-mentioned position of connection of the second switch control circuit 450 can thus avoid affecting the portion of the first electrode layer 110 constituting the equivalent inductance.

Referring to fig. 25, the present application also provides a magnetic field enhancing assembly 10. The magnetic field enhancement assembly 10 includes a first electrode layer 110, a second electrode layer 120, a first dielectric layer 100, a second external capacitance 442, a third external capacitance 443, and a second switch control circuit 450. The first dielectric layer 100 includes a first surface 101 and a second surface 102 disposed opposite each other. The first electrode layer 110 is disposed on the first surface 101, and the first electrode layer 110 covers a portion of the first surface 101. The second electrode layer 120 is disposed on the second surface 102. The second electrode layer 120 covers a portion of the second surface 102. The orthographic projection of the first electrode layer 110 on the first dielectric layer 100 and the orthographic projection of the second electrode layer 120 on the first dielectric layer 100 are overlapped to form a first structural capacitor 150. One end of the third external capacitor 443 is connected to the second electrode layer 120. The other end of the third external capacitor 443 is connected to one end of the second external capacitor 442 and one end of the second switch control circuit 450, respectively. The other end of the second external capacitor 442 and the other end of the second switch control circuit 450 are connected to the first electrode layer 110, respectively. The second switch control circuit 450 is configured to be turned on during a radio frequency transmitting phase and turned off during a radio frequency receiving phase.

It is to be appreciated that the implementation of the second switch control circuit 450 may be the same as or similar to the above embodiment, and will not be repeated here.

Referring to fig. 26, in one embodiment, the magnetic field enhancement assembly 10 further includes a fourth external capacitor 444, a fifth external capacitor 445, and a third switch control circuit 460. Both ends of the fourth external capacitor 444 are connected to the first electrode layer 110 and the second electrode layer 120, respectively. One end of the fifth external capacitor 445 is connected to the second electrode layer 120, the other end of the fifth external capacitor 445 is connected to one end of the third switch control circuit 460, the other end of the third switch control circuit 460 is connected to the first electrode layer 110, and the third switch control circuit 460 is used for being turned on in a radio frequency transmitting stage and turned off in a radio frequency receiving stage.

The first electrode layer 110 and the second electrode layer 120 have overlapping portions in the orthographic projection of the first dielectric layer 100. The fourth electrode layer 140 and the first electrode layer 110 have overlapping portions in the orthographic projection of the first dielectric layer 100. Accordingly, in the overlapping portion, the first electrode layer 110, the second electrode layer 120, and the first dielectric layer 100 may constitute a second structural capacitance 152. The first electrode layer 110, the fourth electrode layer 140, and the first dielectric layer 100 may constitute a third structural capacitance 153.

The first electrode layer 110, the second electrode layer 120, and the fourth electrode layer 140 may form an equivalent inductance at a portion where the first dielectric layer 100 is not overlapped. The second structural capacitor 152, the third structural capacitor 153, and the equivalent inductance may constitute an LC oscillating circuit. When the magnetic field enhancement device 20 formed by the magnetic field enhancement assemblies 10 is placed in the magnetic resonance system, the frequency of the magnetic field enhancement device 20 formed by the magnetic field enhancement assemblies 10 is equal to that of a radio frequency coil in the magnetic resonance system by arranging a proper LC oscillating circuit under the action of an excitation field. A plurality of the magnetic field enhancement assemblies 10 cooperate to enhance the rf transmit field and the rf receive field.

The fourth external capacitor 444 and the fifth external capacitor 445 may be fixed capacitors or tunable capacitors. When the environment in which the magnetic field enhancement assembly 10 is used is determined, for example, after the frequency of the rf coil is determined, a suitable fixed capacitor may be selected so that the resonant frequency of the magnetic field enhancement device 20 formed by the plurality of magnetic field enhancement devices 10 is equal to the frequency of the rf coil, thereby enhancing the magnetic field. The fourth external capacitor 444 and the fifth external capacitor 445 may employ tunable capacitors when the environment in which the magnetic field enhancing device 10 is used is not determined, for example, when the frequency of the rf coil is not determined. The resonant frequency of the magnetic field enhancement device 20 formed by the magnetic field enhancement assembly 10 can be adjusted by adjusting the adjustable capacitance to adapt the magnetic field enhancement device 10 to different environments.

The radio frequency transmit phase and the radio frequency receive phase differ in time sequence by tens to thousands of milliseconds. The radio frequency power of the radio frequency transmit phase and the radio frequency receive phase differ by 3 orders of magnitude. The voltage on the structure capacitance during the rf transmission phase is between a few volts and a few hundred volts. And during the rf receiving phase, the voltages across the second structure capacitor 152 and the third structure capacitor 153 are in millivolt level.

The third switch control circuit 460 and the fifth external capacitor 445 are connected in series between the first electrode layer 110 and the second electrode layer 120. In one embodiment, one end of the third switch control circuit 460 is connected to one end of the fifth external capacitor 445, and the other end of the third switch control circuit 460 is connected to the first electrode layer 110. The other end of the fifth external capacitor 445 is connected to the second electrode layer 120. In one embodiment, one end of the third switch control circuit 460 is connected to one end of the fifth external capacitor 445. The other end of the third switch control circuit 460 is connected to the second electrode layer 120. The other end of the fifth external capacitor 445 is connected to the first electrode layer 110.

Therefore, when the third switch control circuit 460 is turned on, the fifth external capacitor 445 and the fourth external capacitor 444 are connected in parallel to the first electrode layer 110 and the second electrode layer 120. When the total capacitance of the magnetic field enhancement assembly 10 is equal, the capacitance of the fifth external capacitor 445 and the fourth external capacitor 444 in parallel is greater than the capacitance of the two capacitors in series. The capacitance values of the second structure capacitance 152 and the third structure capacitance 153 can be smaller, and the magnetic field enhancement assembly 10 has lower losses.

During the radio frequency transmission phase, the resonance frequency of the magnetic field enhancement device 20 formed by the magnetic field enhancement assembly 10 deviates far from the operating frequency of the magnetic resonance system. By connecting the fifth external capacitor 445 and the fourth external capacitor 444 appropriately, it is ensured that the original magnetic field strength of the region to be detected is maintained in the radio frequency emission phase of the magnetic resonance system, and the interference of the magnetic field enhancement assembly 10 to the radio frequency emission phase is eliminated, so that the clinical practicability of the magnetic field enhancement device 20 formed by a plurality of magnetic field enhancement assemblies 10 can be effectively improved. So that the magnetic field enhancement assembly 20 is applicable to all sequences of magnetic resonance systems.

During the rf emission phase, the voltage difference between the first electrode layer 110 and the second electrode layer 120 is larger, and the third switch control circuit 460 is turned on. The fourth external capacitor 444 and the fifth external capacitor 445 are connected in series between the first electrode layer 110 and the second electrode layer 120.

And during the rf receiving phase, the voltage difference between the first electrode layer 110 and the second electrode layer 120 is small, and the third switch control circuit 460 is turned off. The fourth external capacitor 444 is connected in series between the first electrode layer 110 and the second electrode layer 120. When the fourth external capacitor 444 is a fixed capacitor, by selecting an appropriate fourth external capacitor 444, the resonance frequency of the magnetic field enhancement device 20 formed by the magnetic field enhancement devices 20 formed by the magnetic field enhancement assemblies 10 can be equal to the frequency of the radio frequency coil, so that the radio frequency receiving field is greatly enhanced, and the image signal to noise ratio is improved. When the fourth external capacitor 444 is an adjustable capacitor, the resonance frequency of the magnetic field enhancement device 20 formed by the magnetic field enhancement component 10 is equal to the frequency of the radio frequency coil by adjusting the fourth external capacitor 444.

Referring to fig. 27, by providing the fourth external capacitor 444 and the fifth external capacitor 445 appropriately, the magnetic field enhancement device 20 formed by the plurality of magnetic field enhancement components 10 can have a good resonant frequency in the rf receiving stage. Eventually bringing the resonance frequency of the magnetic field enhancing device 20 during the receive phase to the operating frequency of the magnetic resonance system.

The third switch control circuit 460 of the magnetic field enhancement assembly 10 according to the embodiment of the present application is configured to be turned on during a radio frequency transmitting phase and turned off during a radio frequency receiving phase. In the radio frequency emission phase, the resonant frequency of the magnetic field enhancement device 20 formed by the magnetic field enhancement assemblies 10 deviates from the working frequency of the magnetic resonance system, so that by arranging the fifth external capacitor 445 and the fourth external capacitor 444 appropriately, the original magnetic field intensity of the detected region can be kept in the radio frequency emission phase of the magnetic resonance system, the interference of the magnetic field enhancement assemblies 10 on the radio frequency emission phase is eliminated, and the clinical practicability of the magnetic field enhancement device 20 formed by the magnetic field enhancement assemblies 10 can be effectively improved. The magnetic field enhancement assembly 20 is made suitable for all sequences of magnetic resonance systems and reduces adverse effects on the human body.

Referring to fig. 28, in one embodiment, the magnetic field enhancing assembly 10 includes a fifth diode 461 and a sixth diode 462. An anode of the fifth diode 461 is connected to the first electrode layer 110. The cathode of the sixth diode 462 is connected to the first electrode layer 110. One end of the fifth external capacitor 445 is connected to the second electrode layer 120, and the other end of the fifth external capacitor 445 is connected to the cathode of the fifth diode 461 and the anode of the sixth diode 462, respectively.

It is understood that the turn-on voltage of the fifth diode 461 and the sixth diode 462 may be between 0 volts and 1 volt. In one embodiment, the turn-on voltage of the fifth diode 461 and the sixth diode 462 may be 0.8V. The fifth diode 461 and the sixth diode 462 are respectively connected in series between the first electrode layer 110 and the second electrode layer 120, i.e., the fifth diode 461 and the sixth diode 462 are reversely connected.

The induced voltage generated by the first electrode layer 110 and the second electrode layer 120 is also an ac voltage due to the ac characteristic of the radio frequency. In the radio frequency emission phase, the turn-on voltage of the fifth diode 461 and the sixth diode 462 has been exceeded due to the voltage difference between the first electrode layer 110 and the second electrode layer 120. Whichever of the first electrode layer 110 and the second electrode layer 120 has a higher voltage, one of the fifth diode 461 and the sixth diode 462 is always in an on state. Thus, during the rf emission phase, the fourth external capacitor 444 and the fifth external capacitor 445 are connected in parallel between the first electrode layer 110 and the second electrode layer 120.

And in the rf receiving stage, since the voltage difference between the first electrode layer 110 and the second electrode layer is smaller than the turn-on voltage of the fifth diode 461 and the sixth diode 462. Therefore, whichever of the first electrode layer 110 and the second electrode layer 120 has a higher voltage, the fifth diode 461 and the sixth diode 462 are in a non-conductive state. At this time, only the fourth external capacitor 444 is connected between the first electrode layer 110 and the second electrode layer 120 during the rf receiving phase.

Referring to fig. 29, in one embodiment, the third switch control circuit 460 further includes a fifth enhancement MOS transistor 463 and a sixth enhancement MOS transistor 464. The drain electrode of the fifth enhancement MOS transistor 463 is connected to the first electrode layer 110. The gate of the fifth enhancement MOS transistor 463 is connected to the first electrode layer 110. The source of the sixth enhancement MOS transistor 464 is connected to the first electrode layer 110. One end of the fifth external capacitor 445 is connected to the source of the fifth enhancement MOS tube 463, and the other end of the fifth external capacitor 445 is connected to the drain of the sixth enhancement MOS tube 464 and the gate of the sixth enhancement MOS tube 464, respectively.

It will be appreciated that the fifth enhancement MOS 463 and the sixth enhancement MOS 464 are non-conductive when the gate voltage is less than the threshold voltage, i.e. a conductive channel is only present when the magnitude of the gate voltage is greater than its threshold voltage.

In the rf emission phase, since the voltage difference between the first electrode layer 110 and the second electrode layer 120 exceeds the threshold voltage at which the fifth enhancement MOS transistor 463 and the sixth enhancement MOS transistor 464 are turned on, no matter which of the first electrode layer 110 and the second electrode layer 120 is high, one of the fifth enhancement MOS transistor 463 and the sixth enhancement MOS transistor 464 is in the on state. Thus, during the rf emission phase, the fourth external capacitor 444 and the fifth external capacitor 445 are connected in parallel between the first electrode layer 110 and the second electrode layer 120.

In the rf receiving stage, the voltage difference between the first electrode layer 110 and the second electrode layer is smaller than the on threshold voltage of the fifth enhancement MOS transistor 463 and the sixth enhancement MOS transistor 464. Therefore, whichever of the first electrode layer 110 and the second electrode layer 120 has a higher voltage, the fifth enhancement MOS transistor 463 and the sixth enhancement MOS transistor 464 are in a non-conductive state. Thus, during the rf receiving phase, the fourth external capacitor 444 is connected between the first electrode layer 110 and the second electrode layer 120.

In one embodiment, one end of the third switch control circuit 460 is connected to a position where the first electrode layer 110 and the second electrode layer 120 have overlapping portions in the orthographic projection of the first dielectric layer 100. The other end of the third switch control circuit 460 is connected to a position where the second electrode layer 120 and the first electrode layer 110 have a superposition portion in the front projection of the first dielectric layer 100. That is, the third switch control circuit 460 can be connected to the first electrode layer 110 at a position where the first electrode layer 110 forms part of the second structure capacitor 152. That is, the third switch control circuit 460 is prevented from being connected to the portion of the first electrode layer 110 that does not constitute the second structure capacitor 152 and the third structure capacitor 153, and thus the portion of the first electrode layer 110 that constitutes the equivalent inductance is prevented from being affected.

Referring to fig. 30, the present application also provides a magnetic field enhancing assembly 10. The magnetic field enhancement assembly 10 includes a first electrode layer 110, a second electrode layer 120, a first dielectric layer 100, the fourth external capacitance 444, the fifth external capacitance 445, and the third switch control circuit 460. The first dielectric layer 100 includes a first surface 101 and a second surface 102 disposed opposite each other. The first electrode layer 110 is disposed on the first surface 101, and the first electrode layer 110 covers a portion of the first surface 101. The second electrode layer 120 is disposed on the second surface 102. The second electrode layer 120 covers a portion of the second surface 102. The orthographic projection of the first electrode layer 110 on the first dielectric layer 100 and the orthographic projection of the second electrode layer 120 on the first dielectric layer 100 are overlapped to form a first structural capacitor 150. Both ends of the fourth external capacitor 444 are connected to the first electrode layer 110 and the second electrode layer 120, respectively. The fifth external capacitor 445 and the third switch control circuit 460 are connected in series between the first electrode layer 110 and the second electrode layer 120. The third switch control circuit 460 is configured to be turned on during a radio frequency transmitting period and turned off during a radio frequency receiving period. The implementation of the third switch control circuit 460 may be the same as or similar to the above embodiment, and will not be described herein.

Referring to fig. 31, an embodiment of the present application provides a magnetic field enhancement assembly 10, which includes a first dielectric layer 100, a first electrode layer 110, a second electrode layer 120, a third electrode layer 130, a fourth electrode layer 140, and the seventh control circuit 630.

The first dielectric layer 100 has opposite first and second ends 103, 104. The first dielectric layer 100 includes opposing first and second surfaces 101, 102. The first electrode layer 110 and the third electrode layer 130 are disposed proximate the first end 103. The second electrode layer 120 and the fourth electrode layer 140 are disposed proximate the second end 104. The front projection of the first electrode layer 110 on the first dielectric layer 100 overlaps the front projection of the third electrode layer 130 on the first dielectric layer 100. The first electrode layer 110, the first dielectric layer 100 and the third electrode layer 130 constitute a fourth structural capacitance 302. The orthographic projection of the second electrode layer 120 on the first dielectric layer 100 overlaps the orthographic projection of the fourth electrode layer 140 on the first dielectric layer 100. The second electrode layer 120, the first dielectric layer 100 and the fourth electrode layer 140 constitute a fifth structural capacitance 303.

The seventh control circuit 630 includes a third capacitor 223, a first inductor 241, and a first switch circuit 631. One end of the third capacitor 223 is connected to the first electrode layer 110. The other end of the third capacitor 223 is connected to the second electrode layer 120. One end of the first inductor 241 is connected to the second electrode layer 120. The first switch circuit 631 is connected between the other end of the first inductor 241 and the first electrode layer 110. The first switch circuit 631 is configured to be turned off during a radio frequency reception phase. The first switch circuit 631 is further configured to be turned on during a radio frequency transmission stage, so that the seventh control circuit 630 is in a high-impedance state.

The first switch circuit 631 in the magnetic field enhancement assembly 10 according to the embodiment of the present application is configured to be turned off during a radio frequency receiving phase. The fourth structure capacitor 302 and the fifth structure capacitor 303 are connected through the third capacitor 223. The first switching circuit 631 and the first inductor 241 do not participate in the circuit conduction. The first switch circuit 631 is further configured to be turned on during a radio frequency transmission stage, and the third capacitor 223 is connected in parallel with the first inductor 241, so that the seventh control circuit 630 is in a high-resistance state. The fourth structure capacitor 302 and the fifth structure capacitor 303 are disconnected. In the rf signal emission stage, almost no current flows between the fourth structural capacitor 302 and the fifth structural capacitor 303, and the magnetic field generated by the magnetic field enhancing component 10 is weakened, so that the influence of the magnetic field enhancing component 10 on the magnetic field in the rf signal emission stage is reduced, thereby reducing the artifact of the detected image and improving the definition of the detected image.

The first switching circuit 631 may be controlled by a control circuit. In one embodiment, the first switching circuit 631 includes a switching element and a control terminal. One end of the switching element is connected to one end of the first inductor 241 remote from the second electrode layer 120. The other end of the switching element is connected to the first electrode layer 110. The control end is connected with an external control device. The control terminal is used for receiving the closing and opening commands. And in the radio frequency transmitting stage, the control device outputs a closing command to the control end. When the control terminal receives a close command, the first inductor 241 is electrically connected to the first electrode layer 110. The first inductor 241 is connected in parallel with the third capacitor 223 and is in a high-resistance state; almost no current flows between the first electrode layer 110 and the second electrode layer 120.

In the radio frequency receiving stage, the control device outputs a closing command to the control end. When the control terminal receives a turn-off command, the first inductor 241 is turned off from the first electrode layer 110. The first electrode layer 110 and the third capacitor 223 are connected in series with the second electrode layer 120, and form a part of a resonant circuit. The magnetic field enhancement device 20 formed by a plurality of the magnetic field enhancement components restores resonance and greatly enhances the radio frequency receiving field.

In one embodiment, the first switching circuit 631 includes a seventh diode 213 and an eighth diode 214. The anode of the seventh diode 213 is connected to the first electrode layer 110. The negative electrode of the seventh diode 213 is connected to the other end of the first inductor 241. The anode of the eighth diode 214 is connected to the other end of the first inductor 241, and the cathode of the eighth diode 214 is connected to the first electrode layer 110.

The magnetic field enhancement assembly 10 is applied to an MRI system to enhance the magnetic field strength of a human feedback signal during a radio frequency reception phase. In the radio frequency transmission phase of an MRI system, the magnetic field energy in the transmission phase is more than 1000 times of the magnetic field energy in the receiving phase. The induction voltage of the magnetic field enhancing assembly 10 during the transmit phase is between tens of volts and hundreds of volts. The induction voltage of the magnetic field enhancement assembly 10 during the receiving phase is less than 1V.

The seventh diode 213 and the eighth diode 214 are connected in anti-parallel. In the radio frequency transmitting stage, the radio frequency coil transmits radio frequency transmitting signals, and the field intensity of the magnetic field is larger. The induced voltage generated by the magnetic field enhancing assembly 10 is relatively large. The voltage applied across the seventh diode 213 and the eighth diode 214 is alternately positive and negative. The applied voltage exceeds the turn-on voltage of the seventh diode 213 and the eighth diode 214, and the seventh diode 213 and the eighth diode 214 are turned on. The third capacitor 223 is connected in parallel with the first inductor 241, so that the seventh control circuit 630 is in a high-resistance state. In the rf signal emission stage, almost no current flows between the fourth structural capacitor 302 and the fifth structural capacitor 303, and the magnetic field generated by the magnetic field enhancing component 10 is weakened, so that the influence of the magnetic field enhancing component 10 on the magnetic field in the rf signal emission stage is reduced, thereby reducing the artifact of the detected image and improving the definition of the detected image.

In the radio frequency receiving stage, the detection part transmits a feedback signal, and the field intensity of the magnetic field is smaller. The magnetic field enhancing assembly 10 produces a small induced voltage. The applied voltage cannot reach the turn-on voltage of the seventh diode 213 and the eighth diode 214, and the seventh diode 213 and the eighth diode 214 are not turned on. The fourth structural capacitor 302 and the fifth structural capacitor 303 are connected through the third capacitor 223, and the magnetic field enhancement device 20 formed by the magnetic field enhancement assemblies 10 is in a resonance state, so as to play a role in enhancing the magnetic field.

In one embodiment, the turn-on voltages of the seventh diode 213 and the eighth diode 214 are each between 0 and 1V. In one embodiment, the turn-on voltages of the seventh diode 213 and the eighth diode 214 are the same, so that the magnetic field strength is continuously increased during the rf receiving stage of the magnetic field enhancement device 20, and the stability of the feedback signal is improved. In one embodiment, the turn-on voltage of the seventh diode 213 and the eighth diode 214 is 0.8V.

In one embodiment, the seventh diode 213 and the eighth diode 214 have the same model, and the voltage drops after the seventh diode 213 and the eighth diode 214 are turned on are the same, so that the magnetic field strength of the magnetic field enhancement device 20 is increased by the same magnitude in the radio frequency receiving stage, and the stability of the feedback signal is further improved.

Referring to fig. 32, in one embodiment, the first switch circuit 631 includes a seventh enhancement MOS transistor 235 and an eighth enhancement MOS transistor 236. The drain and the gate of the seventh enhancement MOS transistor 235 are respectively connected to one end of the first inductor 241 away from the second electrode layer 120. The source of the seventh enhancement MOS transistor 235 is connected to the first electrode layer 110. The drain and the gate of the eighth enhancement MOS transistor 236 are respectively connected to the first electrode layer 110. The source electrode of the eighth enhancement MOS transistor 236 is connected to one end of the first inductor 241 away from the second electrode layer 120.

The seventh enhancement MOS transistor 235 and the eighth enhancement MOS transistor 236 are connected in anti-parallel. In the radio frequency transmitting stage, the radio frequency coil transmits radio frequency transmitting signals, and the field intensity of the magnetic field is larger. The induced voltage generated by the magnetic field enhancing assembly 10 is relatively large. The voltages applied to the two ends of the seventh enhancement MOS transistor 235 and the eighth enhancement MOS transistor 236 are alternately positive and negative. When the voltage applied exceeds the channel turn-on voltage of the seventh enhancement MOS tube 235 and the eighth enhancement MOS tube 236, the source-drain electrode of the seventh enhancement MOS tube 235 is turned on and the source-drain electrode of the eighth enhancement MOS tube 236 is turned on alternately. The third capacitor 223 is connected in parallel with the first inductor 241, so that the seventh control circuit 630 is in a high-resistance state. In the rf signal emission stage, almost no current flows between the fourth structural capacitor 302 and the fifth structural capacitor 303, and the magnetic field generated by the magnetic field enhancing component 10 is weakened, so that the influence of the magnetic field enhancing component 10 on the magnetic field in the rf signal emission stage is reduced, thereby reducing the artifact of the detected image and improving the definition of the detected image.

In the radio frequency receiving stage, the detection part transmits a feedback signal, and the field intensity of the magnetic field is smaller. The magnetic field enhancing assembly 10 produces a small induced voltage. The loaded voltage cannot reach the channel conduction voltage of the seventh enhancement MOS tube 235 and the eighth enhancement MOS tube 236, and the source drain of the seventh enhancement MOS tube 235 is conducted and the source drain of the eighth enhancement MOS tube 236 is not conducted. The fourth structural capacitor 302 and the fifth structural capacitor 303 are connected through the third capacitor 223, and the magnetic field enhancement device 20 formed by the magnetic field enhancement assemblies 10 is in a resonance state, so as to play a role in enhancing the magnetic field.

In one embodiment, the channel turn-on voltages of the seventh enhancement MOS transistor 235 and the eighth enhancement MOS transistor 236 are both between 0 and 1V, and the channel turn-on voltages of the seventh enhancement MOS transistor 235 and the eighth enhancement MOS transistor 236 are the same, so that the magnetic field enhancement device 20 can stably enhance the magnetic field in the radio frequency receiving stage, and the feedback signal can stably output. In one embodiment, the channel turn-on voltage of the seventh enhancement MOS transistor 235 and the eighth enhancement MOS transistor 236 is 0.8V.

Referring to fig. 33, in one embodiment, the first electrode layer 110 further includes a first sub-electrode layer 111 and a first connection layer 190. The first sub-electrode layer 111 is connected to the first connection layer 190. The first connection layer 190 is disposed adjacent to the second electrode layer 120. The front projection of the first sub-electrode layer 111 on the first dielectric layer 100 overlaps the front projection of the third electrode layer 130 on the first dielectric layer 100. One end of the third capacitor 223 is connected to one end of the first connection layer 190 near the first sub-electrode layer 111. The other end of the third capacitor 223 is connected to the second electrode layer 120. The first switch circuit 631 is connected between an end of the first connection layer 190 away from the first sub-electrode layer 111 and the second electrode layer 120. The first connection layer 190 constitutes the first inductor 241.

The circuit after the first switch circuit 631 is connected in series with the first connection layer 190 is connected in parallel with the third capacitor 223. The seventh control circuit 630 is connected in series between the first electrode layer 110 and the second electrode layer 120. The first sub-electrode layer 111 and the first connection layer 190 may be formed by spraying. The first sub-electrode layer 111 and the first connection layer 190 are laid in the same layer, so that the process is saved. The first sub-electrode layer 111 is used to form part of the structural capacitance. The first connection layer 190 is used to form a structural inductor, so that no external inductor is needed, and the cost is saved.

Referring to fig. 34, in one embodiment, the width of the first connection layer 190 is smaller than the first sub-electrode layer 111. The magnetic field enhancement component 10 covers the detection part and enhances the magnetic field of the feedback signal of the detection part in a resonance mode. Since the width of the first connection layer 190 in the magnetic field enhancement assembly 10 is smaller than the width of the first sub-electrode layer 111, the area of the detection portion covered by the first electrode layer 110 is reduced, the shielding effect of the first electrode layer 110 is reduced, and the transmission capability of the feedback signal is enhanced. The radio frequency coil is easier to receive feedback signals, so that the quality of the received signals is improved, and the quality of images formed after the signals are processed is improved. In addition, when a plurality of the magnetic field enhancement assemblies 10 are used in cooperation, the area of relative overlap between the first connection layers 190 in different magnetic field enhancement assemblies 10 is reduced, stray capacitance formed by the first connection layers 190 in different magnetic field enhancement assemblies 10 and air is reduced, coupling effect is reduced, and signal quality is improved.

Referring also to fig. 35, in one embodiment, the magnetic field enhancement assembly 10 further includes a fifth electrode layer 141. The fifth electrode layer 141 is disposed on the second surface 102 and is disposed between the third electrode layer 130 and the fourth electrode layer 140 at intervals. The front projection of the fifth electrode layer 141 on the first dielectric layer 100 overlaps with the front projection of the first electrode layer 110 on the first dielectric layer 100. The fifth electrode layer 141, the first dielectric layer 100 and the first electrode layer 110 constitute the sixth structural capacitance 304. The front projection of the fifth electrode layer 141 on the first dielectric layer 100 overlaps the front projection of the second electrode layer 120 on the first dielectric layer 100. The fifth electrode layer 141, the first dielectric layer 100, and the second electrode layer 120 constitute the third capacitor 223.

The fifth structure capacitor 303, the third capacitor 223, the sixth structure capacitor 304, and the fourth structure capacitor 302 are connected in series. Other non-capacitive structural portions of the first electrode layer 110 and the second electrode layer 120 are used for conduction. The first switch circuit 631 and the first inductor 241 are connected in series to form a first circuit. A second circuit is formed by connecting a portion of the fifth electrode layer 141 opposite to the second electrode layer 120 in series with the sixth structural capacitor 304. The first circuit and the second circuit are connected in parallel to form the seventh control circuit 630. The seventh control circuit 630 uses the paved electrode to form a capacitor, so that an external capacitor is not needed, and the cost is saved.

Referring to fig. 36, in one embodiment, the seventh control circuit 630 further includes a third inductor 243. The first inductor 241, the first switching circuit 631, and the third inductor 243 are sequentially connected in series. One end of the third inductor 243 is connected to the first electrode layer 110. The other end of the third inductor 243 is connected to the first switch circuit 631. The first inductor 241 and the third inductor 243 are respectively connected to two ends of the first switch circuit 631, so as to increase the symmetry of the structure of the magnetic field enhancement assembly 10, further increase the symmetry of the magnetic field enhancement assembly 10, and reduce distortion caused by inconsistent magnetic field enhancement.

Referring to fig. 37, in one embodiment, the seventh control circuit 630 further includes a fourth capacitor 224. The fourth capacitor 224 is connected between the third capacitor 223 and the first electrode layer 110. The fourth capacitor 224 is connected in series with the third capacitor 223. The fourth capacitor 224 is configured to reduce the voltage division of the third capacitor 223, improve the capability of the magnetic field enhancing component 10 to resist a strong magnetic field, and reduce the probability of breakdown of the third capacitor 223.

In one embodiment, the capacitance values of the fourth structure capacitance 302, the fifth structure capacitance 303, the third capacitance 223, and the fourth capacitance 224 are all equal. In the rf receiving stage, the voltage division on the fourth structural capacitor 302, the fifth structural capacitor 303, the third capacitor 223 and the fourth capacitor 224 is the same, so as to improve the uniformity of the magnetic field, reduce the distortion caused by inconsistent enhancement of the magnetic field, and improve the image quality.

Referring to fig. 38 and 39, an embodiment of the present application provides a magnetic field enhancement assembly 10 including a first dielectric layer 100, a first electrode layer 110, a second electrode layer 120, and a third electrode layer 130. The first dielectric layer 100 has opposite first and second ends 103, 104. The first dielectric layer 100 further includes opposing first and second surfaces 101, 102.

The first electrode layer 110 is disposed on the first surface 101. The first electrode layer 110 extends along the first end 103 towards the second end 104. The first electrode layer 110 includes a first sub-electrode layer 111, a second sub-electrode layer 112, and a first connection layer 190. The first sub-electrode layer 111 and the second sub-electrode layer 112 have the same width. The first sub-electrode layer 111 and the second sub-electrode layer 112 are disposed at a relative interval. One end of the first connection layer 190 is connected to the first sub-electrode layer 111. The other end of the first connection layer 190 is connected to the second sub-electrode layer 112. The width of the first connection layer 190 is smaller than the width of the first sub-electrode layer 111 or the second sub-electrode layer 112.

The second electrode layer 120 and the third electrode layer 130 are disposed on the second surface 102 at opposite intervals. The orthographic projection of the second electrode layer 120 on the first dielectric layer 100 overlaps with the orthographic projection of the first sub-electrode layer 111 on the first dielectric layer 100. The second electrode layer 120, the first dielectric layer 100 and the first sub-electrode layer 111 constitute a fourth structural capacitance 302. The orthographic projection of the third electrode layer 130 on the first dielectric layer 100 overlaps the orthographic projection of the second sub-electrode layer 112 on the first dielectric layer 100. The third electrode layer 130, the first dielectric layer 100 and the second sub-electrode layer 112 constitute a fifth structural capacitance 303.

The fourth structural capacitor 302 and the fifth structural capacitor 303 are connected through the first connection layer 190 to form a resonant circuit. When the magnetic field enhancing component 10 covers the detection part, the magnetic field of the feedback signal of the detection part is enhanced by a resonance mode. In the magnetic field enhancement assembly 10 according to the embodiment of the present application, the width of the first connection layer 190 is smaller than the width of the first sub-electrode layer 111. The area of the detection portion covered by the first electrode layer 110 is reduced, the shielding effect of the first electrode layer 110 is reduced, and the transmission capability of the feedback signal is enhanced. The radio frequency coil is easier to receive feedback signals, so that the quality of the received signals is improved, and the quality of images formed after the signals are processed is improved.

In addition, when a plurality of the magnetic field enhancement assemblies 10 are used in cooperation, the area of relative overlap between the first connection layers 190 in different magnetic field enhancement assemblies 10 is reduced, stray capacitance formed by the first connection layers 190 in different magnetic field enhancement assemblies 10 and air is reduced, coupling effect is reduced, and signal quality is improved.

The first dielectric layer 100 may function to support the first electrode layer 110, the second electrode layer 120, and the third electrode layer 130. The first dielectric layer 100 may be an insulating material. The first dielectric layer 100 may have a rectangular plate-like structure. The first dielectric layer 100 may be an insulating material. In one embodiment, the material of the first dielectric layer 100 may be a glass fiber epoxy plate. The materials of the first electrode layer 110, the second electrode layer 120, and the third electrode layer 130 may be composed of conductive non-magnetic materials. In one embodiment, the materials of the first electrode layer 110, the second electrode layer 120, and the third electrode layer 130 may be metal materials such as gold, silver, copper, and the like. The first electrode layer 110, the second electrode layer 120 and the third electrode layer 130 formed of the above materials have good conductive properties and are easy to manufacture.

In one embodiment, the first sub-electrode layer 111, the second sub-electrode layer 112 and the first connection layer 190 are laid on the same layer, which reduces the process and improves the working efficiency.

In one embodiment, the length and width of the first sub-electrode layer 111 and the second sub-electrode layer 112 are the same. The front projection of the second electrode layer 120 on the first dielectric layer 100 overlaps the front projection of the first sub-electrode layer 111 on the first dielectric layer 100. The orthographic projection of the third electrode layer 130 on the first dielectric layer 100 overlaps the orthographic projection of the second sub-electrode layer 112 on the first dielectric layer 100. The fourth structure capacitor 302 and the fifth structure capacitor 303 have the same capacitance and the same capacitance value. The magnetic field enhancing assembly 10 has a high degree of symmetry. The magnetic field enhancement assembly 10 has a good enhancement effect on the magnetic field of the feedback signal. The enhanced feedback signal magnetic field has higher uniformity, so that the feedback signal has higher quality.

In one embodiment, the length of the first dielectric layer 100 ranges from 100 millimeters to 500 millimeters. In one embodiment, the first dielectric layer 100 has a length of 250 millimeters. The first dielectric layer 100 has a width of 10mm to 30 mm. In one embodiment, the width of the first dielectric layer 100 is 15 millimeters. In one embodiment, the first dielectric layer 100 has a thickness of 0.2 mm to 2 mm. In one embodiment, the thickness of the first dielectric layer 100 is 0.51 millimeters.

The direction from the first end 103 to the second end 104 is a first direction b. The first direction a is perpendicular to the second direction b. The width direction of the second sub-electrode layer 112 is the second direction a.

In one embodiment, the electrical loss of the first connection layer 190 is less than 1/2 of the overall electrical loss of the magnetic field enhancement assembly 10. The first connection layer 190 has a smaller electrical loss, and the magnetic field enhancement assembly 10 has a smaller heating value. The energy of the magnetic field enhancing component 10 is mainly used for generating a magnetic field, and the enhancing effect of the magnetic field in the receiving stage is good.

In one embodiment, the width of the first connection layer 190 is 1/5 to 1/2 of the width of the first sub-electrode layer 111. The width of the first connection layer 190 is 1/5 to 1/2 of the width of the first sub-electrode layer 111, so that the electrical loss of the first connection layer 190 in the magnetic field enhancement assembly 10 can be ensured to be less than 1/2 of the overall electrical loss. The first connection layer 190 has a smaller electrical loss, and the magnetic field enhancement assembly 10 generates a smaller amount of heat. The energy of the magnetic field enhancing component 10 is mainly used for generating a magnetic field, and the enhancing effect of the magnetic field in the receiving stage is good.

In one embodiment, the widths of the first sub-electrode layer 111 and the second sub-electrode layer 112 are 1mm to 30 mm. The first connection layer 190 is 1mm to 15 mm. In one embodiment, the width of the first sub-electrode layer 111 and the second sub-electrode layer 112 is 15 mm, and the width of the first connection layer 190 is 4 mm.

Referring to fig. 40, in one embodiment, an included angle between the extending direction of the first connection layer 190 and the first direction b is an acute angle or an obtuse angle. The first direction b is directed from the first end 103 to the second end 104. When the magnetic field enhancement device 20 includes a cylindrical support structure 50, a first annular conductive sheet 510, a second annular conductive sheet 520, and a plurality of the magnetic field enhancement assemblies 10, the plurality of the magnetic field enhancement assemblies 10 are disposed in parallel with each other on the cylindrical support structure 50 when the cylindrical support structure 50 is a cylindrical structure. A plurality of the magnetic field enhancement assemblies 10 are connected in parallel. In the magnetic field enhancement device 20, the first connection layers 190 in the two opposing magnetic field enhancement modules 10 are staggered, and the parallel overlapping portions are reduced. The stray capacitance formed by the first connection layer 190 and air in the two opposing magnetic field enhancement assemblies 10 is reduced, the coupling effect is reduced, and the signal quality is improved.

Referring to fig. 41, in one embodiment, an arc chamfer is disposed at the intersection of the sidewall of the first connection layer 190 and the sidewall of the first sub-electrode layer 111 or the second sub-electrode 112. The current flows through the first sub-electrode layer 111, the first connection layer 190, and the second sub-electrode layer 112. The width of the first connection layer 190 is smaller than the width of the first sub-electrode layer 112. The current is collected at the junction of the first sub-electrode layer 111 and the first connection layer 190, and the current density increases. The intersection of the side wall of the first connection layer 190 and the side wall of the first sub-electrode layer 111 is provided with an arc chamfer, so that the first connection layer 190 and the first sub-electrode layer 111 are connected through a horn structure, abrupt change of current density is slowed down, and current density at the intersection of the side wall of the first connection layer 190 and the side wall of the first sub-electrode layer 111 is reduced. The current density at the junction of the first connection layer 190 and the first sub-electrode layer 111 is reduced, the heating value is reduced, and the service life of the magnetic field enhancing assembly 10 is prolonged.

The current is collected at the junction of the second sub-electrode layer 112 and the first connection layer 190, and the current density increases. An arc chamfer is disposed at the intersection of the sidewall of the first connection layer 190 and the sidewall of the second sub-electrode layer 112, so that a horn structure is formed at the connection of the first connection layer 190 and the second sub-electrode layer 112. The horn structure formed at the junction of the first connection layer 190 and the second sub-electrode layer 112 can slow down abrupt change of current density, so as to reduce current density at the intersection of the sidewall of the first connection layer 190 and the sidewall of the second sub-electrode layer 112. The current density at the junction of the second sub-electrode layer 112 and the first connection layer 190 is reduced, so that the heating value is reduced, and the service life of the magnetic field enhancing assembly 10 is prolonged.

Referring to fig. 42, in one embodiment, the first electrode layer 110 further includes a second connection layer 191. The width of the second connection layer 191 is smaller than the width of the first sub-electrode layer 111. The second connection layer 191 is disposed on the first surface 101. The second connection layer 191 is disposed in parallel with the first connection layer 190 at a distance, and the first connection layer 190 and the second connection layer 191 are connected in parallel between the first sub-electrode layer 111 and the second sub-electrode layer 112. The first connection layer 190 and the second connection layer 191 are connected in parallel, so that the current density flowing through the first connection layer 190 and the second connection layer 191 can be reduced, and the amount of heat generation can be reduced. The magnetic field enhancement assembly 10 adopts a plurality of connection layers, so that the uniformity of the distribution of the magnetic field of the connection layers in the width direction can be improved, and the uniformity of the enhancement effect of the magnetic field enhancement assembly 10 on the magnetic field of the feedback signal in the width direction of the connection layers is further improved, and the signal quality is improved.

In one embodiment, the extending direction of the first connection layer 190 and the extending direction of the second connection layer 191 form an acute angle or an obtuse angle. When a plurality of the magnetic field enhancement assemblies 10 are distributed in the cylindrical support structure 50 in a circular array, the first connection layers 190 and the second connection layers 191 of the two opposite magnetic field enhancement assemblies 10 are all staggered, and the parallel overlapping portions are reduced. The stray capacitance formed by the first connection layer 190 and air in the two opposite magnetic field enhancement assemblies 10 is reduced, the stray capacitance formed by the second connection layer 191 and air is reduced, the coupling effect is reduced, and the signal quality is improved.

In one embodiment, the extending direction of the first connection layer 190 is asymmetrically arranged with respect to the second connection layer 191. It is understood that the angle between the extending direction of the first connection layer 190 and the second direction b is not equal to the angle between the extending direction of the first connection layer 190 and the second direction b. When a plurality of the magnetic field enhancement assemblies 10 are arranged in parallel in a cylindrical structure, the first connection layers 190 in the magnetic field enhancement assemblies 10 are staggered with the second connection layers 191 in the other magnetic field enhancement assemblies 10, and the parallel overlapping portions are reduced. The stray capacitance formed by the first connection layer 190 in the magnetic field enhancement assembly 10, the second connection layer 191 in the other magnetic field enhancement assemblies 10, and air is reduced, the coupling effect is further reduced, and the signal quality is further improved.

Referring to fig. 43, in one embodiment, the first electrode layer 110 further includes a second connection layer 191. The second connection layer 191 is disposed on the first surface 101. The width of the second connection layer 191 is smaller than the width of the first sub-electrode layer 111. The first sub-electrode layer 111, the first connection layer 190, the second connection layer 191, and the second sub-electrode layer 112 are sequentially arranged along a direction in which the first dielectric layer 100 extends. The first connection layer 190 is spaced apart from the second connection layer 191. The first connection layer 190 is connected to the first sub-electrode layer 111. The second connection layer 191 is connected to the second sub-electrode layer 112. The magnetic field enhancement assembly 10 further includes a second resonant circuit 410. One end of the second resonant circuit 410 is connected to the first connection layer 190. The other end of the second resonant circuit 410 is connected to the second connection layer 191. The second resonant circuit 410 is capable of adjusting the capacitance or resistance of the magnetic field enhancing assembly 10.

In one embodiment, the lengths and widths of the first connection layer 190 and the second connection layer 191 are the same, so as to improve the symmetry of the structure of the magnetic field enhancement assembly 10, further improve the uniformity of the enhancement effect of the magnetic field enhancement assembly 10 on the magnetic field of the feedback signal, and improve the quality of the collected feedback signal (detection signal).

In one embodiment, the second resonant circuit 410 may include a capacitor, one end of which is connected to the first connection layer 190, and the other end of which is connected to the second connection layer 191. The second resonant circuit 410 can reduce the voltage division of the fourth structural capacitor 302 and the fifth structural capacitor 303 by adding a capacitor, and can prevent the breakdown of the capacitor caused by the excessive current generated by electromagnetic induction.

Referring to fig. 44 and 45, the first magnetic field enhancement device 812 includes a second dielectric layer 831, a seventh electrode layer 832, an eighth electrode layer 833, a first depletion MOS 231 and a second depletion MOS 232. The second dielectric layer 831 has a third surface 805. The second dielectric layer 831 has a fifth end 881 and a sixth end 882 disposed opposite thereto. The seventh electrode layer 832 is disposed on the third surface 805. The seventh electrode layer 832 is disposed proximate the sixth end 882. The eighth electrode layer 833 is disposed on the third surface 805. The eighth electrode layer 833 is spaced apart from the seventh electrode layer 832. The eighth electrode layer 833 is disposed adjacent to the fifth end 881. The source of the first depletion MOS 231 is connected to the eighth electrode layer 833. The gate and the drain of the first depletion MOS tube 231 are connected. The gate and drain of the second depletion MOS transistor 232 are connected. The gate and drain of the second depletion MOS transistor 232 are connected to the gate and drain of the first depletion MOS transistor 231. The source of the second depletion MOS transistor 232 is connected to the seventh electrode layer 832.

The first depletion MOS tube 231 and the second depletion MOS tube 232 have the characteristics of low voltage conduction and high voltage cut-off. And, the pinch-off voltage of the first depletion MOS transistor 231 and the second depletion MOS transistor 232 at room temperature is about 1V, and the turn-off time and the recovery time are both in nanosecond order.

The radio frequency transmitting phase and the radio frequency receiving phase in the magnetic resonance system have a difference of tens of milliseconds to thousands of milliseconds in time sequence, so that the first depletion type MOS tube 231 and the second depletion type MOS tube 232 can be rapidly turned on and off. The radio frequency power of the radio frequency transmit phase and the radio frequency receive phase differ by 3 orders of magnitude. The induced voltage in the coil during the radio frequency transmit phase is between a few V and a few hundred V, with specific values being dependent on the chosen sequence and flip angle.

The first depletion MOS tube 231 and the second depletion MOS tube 232 are connected in reverse series, so that the seventh electrode layer 832 and the eighth electrode layer 833 can be controlled to be disconnected in a radio frequency transmitting stage and connected in a radio frequency receiving stage. In the radio frequency emission stage, the first depletion type MOS tube 231 and the second depletion type MOS tube 232 are connected in reverse series, so that the device can be adapted to an alternating current environment in MRI equipment. In any case, it is ensured that one of the first depletion type MOS transistor 231 and the second depletion type MOS transistor 232 is turned off, so that the eighth electrode layer 833 and the seventh electrode layer 832 are disconnected and not connected.

In the radio frequency emission stage, the induced voltage is larger, the first depletion MOS tube 231 and the second depletion MOS tube 232 are in an off state, the first cylindrical magnetic field enhancers 810 formed by the plurality of first magnetic field enhancing components 812 are in an off state, and a detuned state is presented. The absence of current in the first magnetic field strength member 812 does not create an induced magnetic field that would interfere with radio frequency, eliminating the effect of the first cylindrical magnetic field strength member 810 on the magnetic field during the radio frequency emission phase.

In the rf receiving stage, the first depletion MOS 231 and the second depletion MOS 232 are turned on, so as to ensure that the seventh electrode layer 832 is connected to the eighth electrode layer 833. The first cylindrical magnetic field enhancers 810 formed by the plurality of first magnetic field enhancing components 812 are in a connection state, and can be in a resonance state, so that a signal field is greatly enhanced, and an image signal-to-noise ratio is enhanced. Therefore, the seventh electrode layer 832 and the eighth electrode layer 833 are controlled to be disconnected in the radio frequency transmitting stage and connected in the radio frequency receiving stage by the first depletion MOS transistor 231 and the second depletion MOS transistor 232, so that the first magnetic field enhancement component 812 can only enhance the radio frequency receiving field, and can not enhance the radio frequency transmitting field, thereby improving the signal to noise ratio of the image.

The first magnetic field enhancement component 812 introduces a nonlinear control structure through the first depletion MOS transistor 231 and the second depletion MOS transistor 232, so that the first cylindrical magnetic field enhancer 810 formed by the plurality of first magnetic field enhancement components 812 also has nonlinear response characteristics, and can be applied to all clinical sequences including fast spin echo sequences.

In one embodiment, the second dielectric layer 831 further includes a fourth surface 806. The fourth surface 806 is disposed opposite the third surface 805. The first magnetic field enhancement component 812 also includes a ninth electrode layer 834 and the tenth electrode layer 835. The ninth electrode layer 834 is disposed on the fourth surface 806. The ninth electrode layer 834 covers a portion of the fourth surface 806. The ninth electrode layer 834 is disposed proximate the sixth end 882. The tenth electrode layer 835 is disposed on the fourth surface 806. The tenth electrode layer 835 covers a portion of the fourth surface 806. The tenth electrode layer 835 is disposed near the fifth end 881.

The orthographic projection of the ninth electrode layer 834 on the second dielectric layer 831 and the orthographic projection of the seventh electrode layer 832 on the second dielectric layer 831 are partially overlapped to form a seventh structural capacitor 808. In the heavy and portions, the seventh electrode layer 832, the second dielectric layer 831, and the ninth electrode layer 834 form the seventh structural capacitance 808. The orthographic projection of the tenth electrode layer 835 on the second dielectric layer 831 and the orthographic projection of the eighth electrode layer 833 on the second dielectric layer 831 are overlapped to form a sixth structural capacitor 807. In the heavy and partial, the eighth electrode layer 833, the second dielectric layer 831, and the tenth electrode layer 835 form the sixth structural capacitance 807.

The eighth electrode layer 833 between the sixth structure capacitance 807 and the first depletion MOS transistor 231 may form a first transmission line. The seventh electrode layer 832 between the second depletion MOS transistor 232 and the seventh structural capacitor 808 may form a second transmission line. The sixth structure capacitor 807, the first depletion MOS transistor 231, the second depletion MOS transistor 232, and the seventh structure capacitor 808 are connected in series through a first transmission line and a second transmission line. Therefore, by connecting the sixth structure capacitor 807, the first depletion MOS transistor 231, the second depletion MOS transistor 232, and the seventh structure capacitor 808 in series, the resonant frequency of the first cylindrical magnetic field enhancer 810 formed by the plurality of first magnetic field enhancing members 812 can be adjusted, and the adjustment time of the first cylindrical magnetic field enhancer 810 after being put into the nuclear magnetic resonance imaging system can be shortened.

The first magnetic field enhancement component 812 generates an induced voltage in a magnetic field environment. The transmission line portion formed by the seventh electrode layer 832 and the eighth electrode layer 833 may form parasitic capacitance. The parasitic capacitance is in parallel relationship with the seventh structure capacitance 808 and the sixth structure capacitance 807. In the rf receiving stage, the sixth structure capacitor 807 and the seventh structure capacitor 808 form a capacitor series structure, dividing the induced voltage into a plurality of parts, and reducing the voltage division between the sixth structure capacitor 807 and the seventh structure capacitor 808.

Further, the sixth structure capacitor 807 and the seventh structure capacitor 808 form a capacitor series structure, which can reduce the voltage on the parasitic capacitor. The voltage on the parasitic capacitance is reduced, and the harm of the parasitic capacitance is reduced, so that the load effect is reduced. The load effect of the first magnetic field enhancement component 812 is reduced, so that the resonance frequency of the first cylindrical magnetic field enhancer 810 formed by the plurality of first magnetic field enhancement components 812 is not easily affected by the object to be tested, enhancing the enhancement performance of the first cylindrical magnetic field enhancer 810, and enhancing the stability of the resonance frequency.

The embodiment of the application also provides a magnetic resonance system. The magnetic resonance system comprises the magnetic field enhancing means 20.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples merely represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the patent. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. A magnetic field enhancing device, comprising:

a cylindrical support structure (50) having two spaced-apart opposed third (51) and fourth (53) ends;

A plurality of magnetic field enhancement assemblies (10) disposed at spaced apart intervals on the cylindrical support structure (50) and extending along the third end (51) toward the fourth end (53); and

A first annular conductive sheet (510) disposed on the cylindrical support structure (50) and adjacent to the third end (51), the first annular conductive sheet (510) having a fifth opening (501), the fifth opening (501) being at least partially disposed between two adjacent magnetic field enhancement assemblies (10), the first annular conductive sheet (510) being electrically connected to portions of the plurality of magnetic field enhancement assemblies (10) disposed at the third end (51); and

A second annular conductive sheet (520) disposed on the cylindrical support structure (50) and adjacent to the fourth end (53), the second annular conductive sheet (520) having a sixth opening (502), the sixth opening (502) being at least partially located between two adjacent magnetic field enhancement assemblies (10), the second annular conductive sheet (520) being electrically connected to portions of the plurality of magnetic field enhancement assemblies (10) located at the fourth end (53); wherein the fifth opening (501) and the sixth opening (502) are located between two adjacent magnetic field enhancing assemblies (10), and the arc length corresponding to the fifth opening (501) and the arc length corresponding to the sixth opening (502) are one third to one half of the arc length between two adjacent magnetic field enhancing assemblies (10).

2. The magnetic field enhancement device according to claim 1, wherein at the third end (51) the magnetic field enhancement assembly (10) is sandwiched between the cylindrical support structure (50) and the first annular conductive sheet (510), and at the fourth end (53) the magnetic field enhancement assembly (10) is sandwiched between the cylindrical support structure (50) and the second annular conductive sheet (520).

3. The magnetic field enhancing device of claim 1, wherein the cylindrical support structure (50) has a central symmetry plane (506) between the third end (51) and the fourth end (53), the fifth opening (501) and the sixth opening (502) being symmetrical about the central symmetry plane (506).

4. The magnetic field enhancement device according to claim 1, wherein the magnetic field enhancement assembly (10) comprises:

a first dielectric layer (100) comprising a first surface (101) and a second surface (102) arranged opposite each other;

A first electrode layer (110) disposed on the first surface (101), the first electrode layer (110) covering a portion of the first surface (101), the first electrode layer (110) being connected to the first annular conductive sheet (510);

The second electrode layer (120) is arranged on the second surface (102), the second electrode layer (120) covers part of the second surface (102), the projection of the first electrode layer (110) on the first dielectric layer (100) is overlapped with the projection of the second electrode layer (120) on the first dielectric layer (100), and the second electrode layer (120) is connected with the second annular conducting plate (520).

5. The magnetic field enhanced device of claim 4, wherein an area occupied by a portion of the orthographic projection of the first electrode layer (110) on the first dielectric layer (100) and the orthographic projection of the second electrode layer (120) on the first dielectric layer (100) is less than half an area of the first surface (101) or half an area of the second surface (102).

6. The magnetic field enhancement device of claim 4, wherein the magnetic field enhancement assembly (10) further comprises a first external capacitor (440), both ends of the first external capacitor (440) being connected to the first electrode layer (110) and the second electrode layer (120), respectively.

7. The magnetic field enhancement device of claim 4, wherein the portion of the first electrode layer (110) and the second electrode layer (120) that are coincident in the projection of the first dielectric layer (100) is located in the middle of the first dielectric layer (100).

8. The magnetic field enhancement device of claim 7, further comprising:

The third electrode layer (130) is arranged on the first surface (101) and is arranged at intervals with the first electrode layer (110), the first dielectric layer (100) comprises a first end (103) and a second end (104) which are opposite, the third electrode layer (130) extends from the first end (103) to the second end (104) and covers part of the first surface (101), and the second electrode layer (120) is electrically connected with the third electrode layer (130).

9. The magnetic field enhancement device of claim 4, wherein an end of the first electrode layer (110) adjacent to the second electrode layer (120) has a first opening (411), an end of the second electrode layer (120) adjacent to the first electrode layer (110) has a second opening (412), and the orthographic projections of the first opening (411) and the second opening (412) on the first dielectric layer (100) coincide.

10. The magnetic field enhancement device of claim 4, further comprising a first switch control circuit (430), wherein two ends of the first switch control circuit (430) are respectively connected to the first electrode layer (110) and the second electrode layer (120), and wherein the first switch control circuit (430) is configured to be turned on during a radio frequency transmission phase and turned off during a radio frequency reception phase.